Answer:
Assuming b = 9.3i + 9.5j (b = 931 + 9.5 is wrong):
a) a×b = 34.27k
b) a·b = 128.43
c) (a + b)·b = 305.17
d) The component of a along the direction of b = 9.66
Explanation:
Assuming b = 9.3i + 9.5j (b = 931 + 9.5 is wrong) we can proceed as follows:
a) The vectorial product, a×b is:
[tex] a \times b = (8.6*9.5 - 5.1*9.3)k = 34.27k [/tex]
b) The escalar product a·b is:
[tex] a\cdot b = (8.6*9.3) + (5.1*9.5) = 128.43 [/tex]
c) Asumming (a + b)·b instead a+b·b we have:
[tex](a + b)\cdot b = [(8.6 + 9.3)i + (5.1 + 9.5)j]\cdot (9.3i + 9.5j) = (17.9i + 14.6j)\cdot (9.3i + 9.5j) = 305.17[/tex]
d) The component of a along the direction of b is:
[tex] a*cos(\theta) = \frac{a\cdot b}{|b|} = \frac{128.43}{\sqrt{9.3^{2} + 9.5^{2}}} = 9.66 [/tex]
I hope it helps you!
A truck collides with a sports car in a high-speed head-on collision. . The mass of the truck and its contents is 5 times larger than the mass of the car and its contents. Select greater than, less than or equal to. During the collision, the magnitude of the change in momentum of the truck is _____ the magnitude of the change in momentum of the car. A: Greater than B: Less than C: Equal to
Answer:
A: Greater than
Explanation:
Momentum (P) implies product of the mass (m) and velocity (v) of a body.
P = mv
It is measured in kgm/s.
Thus the greater the mass of a body, the more its momentum even when moving at a slower velocity. The change in momentum of an object is called its impulse.
Let the mass of the car be represented by [tex]m_{c}[/tex] and that of the truck be represented by [tex]m_{T}[/tex].
Thus,
[tex]m_{T}[/tex] = 5[tex]m_{c}[/tex]
P of the truck = 5[tex]m_{c}[/tex]v
P of the car = [tex]m_{c}[/tex]v
Thus, during collision, the change in momentum of the truck is greater than that of the car.
Answer:
The correct option is B
Explanation:
This question seeks to test the knowledge of the change in momentum and deep understanding of the Newton's first law of motion which states that a substance will continue to be in a state of rest or constant motion unless acted upon by an external force.
The formula for change in momentum is mass multiplied by change in velocity. where change in velocity is final velocity minus the initial velocity.
The mass of the truck is already said to be 5 times larger, the change in velocity of the car will definitely be negative because the car will pushed back by the truck. For instance, if the initial velocity of the car is 50m/s and the final velocity backwards is 10m/s, the change in velocity will be (-10-50) which will equal (-60)
However, for the truck, the change in velocity will still remain positive for the final velocity because it is expected that the truck will still move forward despite the heads-on collision. Hence, if the initial velocity is 50m/s and the final velocity is 10m/s, the change in velocity will be (10-50) which will equal (-40).
Assuming the mass of the car is 1g. From the formula for change in momentum
The truck will be assumed to be (5 × 1) × -40 = -200
The car will be assumed to be 1 × -60 = -60
Hence, the magnitude of change in momentum of the truck will be lesser than the magnitude of the change in momentum of the car.
what is not a property that can be used to identify a mineral?
Answer:
Color.
Explanation:
Hello.
In this case, among the properties minerals have, we list: color , streak which is the color as a powder , hardness , cleavage or fracture , crystalline structure , diaphaneity or degree of transparency, tenacity which is the capacity of its molecules to be held together, magnetism which is the capacity to attract or repel other magnetic materials , luster which explains if its surface reflects light , odor , taste and specific gravity which is a relationship between its density and the density of water.
In such a way, since the most of them are known as measurements, we can distinguish among minerals by contrasting those data, nevertheless, color is not a suitable property to identify a material since there could exist minerals with similar colors.
Best regards.
Iu Metallic bonding is similar to iconic bonding because
Answer:
In an ionic bond the valence electrons are transferred from the metal
Explanation:
Your classmate’s mass is 63 kg and the table weighs 500 N. Calculate the normal force on the table by the floor. Show your work!
Answer:
[tex]F_N=1234.8N[/tex]
Explanation:
Hello.
In this case, since the normal force is opposite to the total present weight, we can compute it by considering the mass of the classmate with the gravity to compute its weight, and the weight of the table:
[tex]F_N=63kg*9.8m/s^2+500N\\\\F_N=617.4N+500N\\\\F_N=1234.8N[/tex]
Best regards.
A car moving with a constant acceleration covers the distance between two points 80 m apart in 8.0 s. Its velocity as it passes the second point is 15 m/s. What was the velocity at the first point? Show work for brainliest!!
Answer:
Explanation:
3.6
Apollo 14 astronaut Alan B. Shepard Jr. used an improvised six-iron to strike two golf balls while on the Fra Mauro region of the moon’s surface, making what some consider the longest golf drive in history. Assume one of the golf balls was struck with initial velocity v0 = 31.75 m/s at an angle θ = 26° above the horizontal. The gravitational acceleration on the moon’s surface is approximately 1/6 that on the earth’s surface. Use a Cartesian coordinate system with the origin at the ball's initial position.
Randomized Variables
vo 32.75 m/s
theta 32 degrees
What horizontal distance, R in meters, did this golf ball travel before returning to the lunar surface?
Complete Question
Apollo 14 astronaut Alan B. Shepard Jr. used an improvised six-iron to strike two golf balls while on the Fra Mauro region of the moon’s surface, making what some consider the longest golf drive in history. Assume one of the golf balls was struck with initial velocity v0 = 32.75 m/s at an angle θ = 32° above the horizontal. The gravitational acceleration on the moon’s surface is approximately 1/6 that on the earth’s surface. Use a Cartesian coordinate system with the origin at the ball's initial position.
Randomized Variables
vo 32.75 m/s
theta 32 degrees
What horizontal distance, R in meters, did this golf ball travel before returning to the lunar surface?
Answer:
The horizontal distance is [tex]R = 590.2 \ m [/tex]
Explanation:
From the question we are told that
The initial velocity is [tex]v_o = 32.75 \ m/s[/tex]
The angle is [tex]\theta = 26^o[/tex]
The gravitational acceleration of the moon is [tex]g_m = \frac{1}{6} * 9.8 = 1.633 m/s^2[/tex]
Generally the distance traveled is mathematically represented as
[tex]R = \frac{v_o^2 sin 2(\theta)}{g_m}[/tex]
=> [tex]R = \frac{32.75^2 sin 2(32)}{1.633}[/tex]
=> [tex]R = 590.2 \ m [/tex]
The water from a fire hose is directed at a building . The water leaves the pipe at a speed of 25 m/s at an angle of 60 deg to the horizontal. If the building is 45 m away, at what height does it hit the building ?
Answer:
Approximately [tex]14\; \rm m[/tex] above the height of the fire hose, assuming that air resistance is negligible and that [tex]g = -9.81\; \rm m \cdot s^{-2}[/tex].
Explanation:
Consider the motion of water particles in two directions: vertical and horizontal.
Assuming that air resistance on the water particles is negligible.
Vertically, water particles would accelerate at [tex](-9.81\; \rm m \cdot s^{-2})[/tex] (towards the ground.)Horizontally, water particles would travel at a constant velocity.Initial velocity: [tex]v_0 = 25\; \rm m \cdot s^{-1}[/tex]. Angle of elevation: [tex]\epsilon = 60^\circ[/tex]. Calculate the initial velocity of these water particles in these two components:
Initial horizontal velocity: [tex]v_0 (\text{horizontal}) = v_0 \cdot \cos\left(\epsilon\right) \approx 12.5\; \rm m \cdot s^{-1}[/tex].Initial vertical velocity: [tex]v_0 (\text{vertical}) = v_0 \cdot \sin\left(\epsilon\right) \approx 21.7\; \rm m \cdot s^{-1}[/tex].How much time would it take for a water particle reaches the building from the hose? That particle needs to travel [tex]x(\text{horizontal}) = 45\; \rm m[/tex] at a constant horizontal speed of [tex]v(\text{horizontal}) \approx 12.5\; \rm m \cdot s^{-1}[/tex]. Therefore:
[tex]\displaystyle t = \frac{x(\text{horizontal})}{v(\text{horizontal})} \approx 3.6\; \rm s[/tex].
In other words, that water particle would be approximately [tex]3.6\; \rm s[/tex] into its flight when it hits the building. What would be its height? Assuming that the air resistance on that particle is negligible. The height of that water particle at time [tex]t[/tex] may be modeled using the SUVAT equation:
[tex]\displaystyle x(\text{vertical}) = \frac{1}{2}\, a \, t^{2} + \left[v_0(\text{vertical})\right]\, t[/tex],
where:
[tex]x(\text{vertical})[/tex] gives the height of the water particle (relative to where it was launched.)[tex]a = g = -9.81\; \rm m \cdot s^{-2}[/tex] (negative because gravitational acceleration points towards the ground.)[tex]v_0(\text{vertical}) \approx 21.7\; \rm m \cdot s^{-1}[/tex] (see above.)[tex]t \approx 3.6\; \rm s[/tex] (that's the time when the water particle hits the building.)Calculate the height of the water particle when it hits the building:
[tex]\begin{aligned}x(\text{vertical}) &= \frac{1}{2}\, a \, t^{2} + \left[v_0(\text{vertical})\right]\, t \\ &\approx \frac{1}{2} \times \left(-9.81\; \rm m \cdot s^{-2}\right) \times (3.6\; \rm s)^2 + 21.7\; \rm m \cdot s^{-1} \times 3.6\; \rm s \\ &\approx 14\; \rm m\end{aligned}[/tex].
who is the first person to reach in space
Answer:
cosmonaut Yuri Gagarin
Explanation:
On that day in 1961, Russian cosmonaut Yuri Gagarin (left, on the way to the launch pad) became the first human in space, making a 108-minute orbital flight in his Vostok 1 spacecraft.
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A 4500 kg car accelerates from rest to 45.0
km/h over a distance of 90 m. Find the net force
acting on the car.
please help
The car undergoes an acceleration a such that
(45.0 km/h)² - 0² = 2 a (90 m)
90 m = 0.09 km, so
(45.0 km/h)² - 0² = 2 a (0.09 km)
Solve for a :
a = (45.0 km/h)² / (2 (0.09 km)) = 11,250 km/h²
Ignoring friction, the net force acting on the car points in the direction of its movement (it's also pulled down by gravity, but the ground pushes back up). Newton's second law then says that the net force F is equal to the mass m times the acceleration a, so that
F = (4500 kg) (11,250 km/h²)
Recall that Newtons (N) are measured as
1 N = 1 kg • m/s²
so we should convert everything accordingly:
11,250 km/h² = (11,250 km/h²) (1000 m/km) (1/3600 h/s)² ≈ 0.868 m/s²
Then the force is
F = (4500 kg) (0.868 m/s²) = 3906.25 N ≈ 3900 N
A projectile is fired with a horizontal velocity of 20 mfs and a vertical velocity of 45
6. What is the magnitude of its original velocity vector?
7. How long will the projectile be in the air?
8. What is its range?
Answer:
6. 49.2 m/s
7. 9.18 s
8. 184 m
Explanation:
6. Use Pythagorean theorem.
v₀² = v₀ₓ² + v₀ᵧ²
v₀² = (20 m/s)² + (45 m/s)²
v₀ = 49.2 m/s
7. Given:
Δy = 0 m
v₀ᵧ = 45 m/s
aᵧ = -9.8 m/s²
Find: t
Δy = v₀ᵧ t + ½ aᵧt²
(0 m) = (45 m/s) t + ½ (-9.8 m/s²) t²
0 = 45t − 4.9t²
0 = t (45 − 4.9t)
t = 9.18 s
8. Given:
v₀ₓ = 20 m/s
aₓ = 0 m/s²
t = 9.18 s
Find: Δx
Δx = v₀ₓ t + ½ aₓt²
Δx = (20 m/s) (9.18 s) + ½ (0 m/s²) (9.18 s)²
Δx = 184 m
What would the kinetic energy and potential energy be with the snowboarder, before during and after a jump?
Answer: Before the jump, the snowboarder would carry potential energy.
During the jump he will carry kinetic energy.
And after the jump, assuming hes at a full stop, he will carry potential energy once again.
Answer:
Before the jump, the snowboarder would carry potential energy.During the jump he will carry kinetic energy.And after the jump, assuming hes at a full stop, he will carry potential energy once again. Explanation:
Which are consequences of smoking while pregnant
Answer:
Explanation:
Tobacco. Smoking during pregnancy increases the risk of health problems for developing babies, including preterm birth, low birth weight, and birth defects of the mouth and lip. Smoking during and after pregnancy also increases the risk of sudden infant death syndrome (SIDS).
Answer:
B I - T H deficits, S l D S, S T I L L . B I - T H
Explanation:
2021 edg .
What does it mean if something is Periodic?
Answer:
In the context of chemistry and the periodic table, periodicity refers to trends or recurring variations in element properties with increasing atomic number. Periodicity is caused by regular and predictable variations in element atomic structure
Explanation:
What are two differences between the dwarf planets and our traditional 8 planets?
Enter Answer Here
How to drawing the resultant vector of two vectors being added:
Answer:
Explanation:
you connect vector b with vector a making it head to tail
How does the eccentricity of a typical cometary orbit compare to that of a typical planet
Answer:
Explanation:
Comets are balls of ice and dust in orbit around the Sun. The orbits of comets are different from those of planets - they are elliptical. A comet's orbit takes it very close to the Sun and then far away again.
A length of 20-gauge copper wire (of diameter 0.8118 mm) is formed into a circular loop with a radius of 25.0 cm. A magnetic field perpendicular to the plane of the loop increases from zero to 10.0 mT in 0.34 s. Find the average electrical power dissipated in the process
Answer:
The average electrical power dissipated in the process is 0.653 mW
Explanation:
Given;
gauge of copper wire, 20 gauge
resistivity from chart, [tex]\rho = 1.68 *10^{-8} \ ohm.m[/tex]
radius of the circular loop, r = 25 cm
magnetic field strength, B = 10 .0 mT
time, t = 0.34 s
Length of the wire, L = 2πr = 2 x π x 0.25 = 1.571 m
Area of the wire, A = πR² ⇒ R = D/2 = 0.8118 mm/ 2 = 0.4059 mm
= π(0.4059 x 10⁻³)² = 0.5177 x 10⁻⁶ m²
The resistance of the wire is given by;
[tex]R = \frac{\rho L}{A}\\\\ R = \frac{1.68*10^{-8}*1.571}{(0.5177*10^{-6})}\\\\ R = 5.098 *10^{-2} \ ohms[/tex]
Now, determine the electric potential;
[tex]E = N\frac{d\phi}{dt}\\\\ E = N(\frac{BA}{dt})\\\\ E = 1(\frac{(10*10^{-3})(\pi*0.25^2)}{0.34} )\\\\E = 0.00577 \ V[/tex]
The average power is given by;
P = V²/R
P = (0.00577²) / (5.098 x 10⁻²)
P = 6.53 x 10⁻⁴ W
P = 0.653 mW
Therefore, the average electrical power dissipated in the process is 0.653 mW
What do seismic waves and sound waves have in common? [Seismic and sound waves]
A They're mechanical waves incorrect answer
B They're electromagnetic waves incorrect answer
C They're phonetic waves incorrect answer
D They're permanent waves
Answer:
D
Explanation:
They continously go back and fourth on the ray of movement making the tremendous exponent of the scientificalsource behind it
d is the answer
lkjhgfdeswwwwwwwwwww3e
I just had to shove an eos in my mouth because I keep shouting random things.....
Answer:
oooop tehehehehehee
ahahhhahaaahahjabasa
Answer:
uhm- heh, wut lol ️️
Which statements are true for two oppositely charged, isolated parallel plates: C=capacitance, U=stored energy (Q and -Q = charge on the plates). Note: Isolated plates can not lose their charge.
1. Inserting a dielectric decreases U.
2. When the distance is doubled, C increases.
3. Increasing the distance increases the Electric field.
4. Inserting a dielectric increases Q.
5. Inserting a dielectric increases C.
6. When the distance is halved, Q stays the same.
7. When the distance is doubled, U increases.
Answer:
Explanation:
1) True. The stored energy (U) is proportional to the electric field strength (E). The electric field strength decreases when a dielectric is introduced hence inserting a dielectric decreases U.
2) False. From the formula [tex]C=\frac{Q}{V}=\frac{Q}{Vd}[/tex], capacitance is inversely proportional to distance hence if the distance is doubled, capacitance decreases.
3) False. As the distance between the electric field and the object increases, its electric field decreases.
4) False. If a dielectric is inserted, the plates are further separated. Q stays the same.
5) True. The electric field strength decreases when a dielectric is introduced and capacitance is inversely proportional to electric field hence Inserting a dielectric increases C
6) True. If a dielectric is inserted, the plates are further separated. Q stays the same.
7) True. When the distance is doubled, U increases
A 6.16-g bullet is moving horizontally with a velocity of 342 m/s, where the sign indicates that it is moving to the right (see part a of the drawing). The bullet is approaching two blocks resting on a horizontal frictionless surface. Air resistance is negligible. The bullet passes completely through the first block (an inelastic collision) and embeds itself in the second one, as indicated in part b. Note that both blocks are moving after the collision with the bullet. The mass of the first block is 1155 g, and its velocity is 0.728 m/s after the bullet passes through it. The mass of the second block is 1517 g.
(a) What is the velocity of the second block after the bullet imbeds itself?
(b) Find the ratio of the total kinetic energy after the collisions to that before the collisions.
Answer:
a
The value is [tex]v = 0.8351 \ m/s [/tex]
b
The ratio is [tex]\frac{K_a}{K_b} = 5.94 11 *10^{-6}[/tex]
Explanation:
From the question we are told that
The mass of the bullet is [tex]m_b = 6.16 \ g = 0.00616 \ kg[/tex]
The velocity is [tex]u_b = 342 \ m/s[/tex]
mass of the first block is [tex]m__{{B_1}}} = 1155 \ g = 1.155 \ kg[/tex]
The velocity of the first block after bullet passes is [tex]v__{{B_1}}} = 0.728 m/s[/tex]
The mass of the second block is [tex]m__{{ B_2}}} = 1517 g = 1.517 \ kg[/tex]
Gnerally according to the law of momentum conservation
[tex]m_b * u_b + m__{{B_1}}} * u__{{B_1}}} = m__{{B_1}}} * v__{{B_1}}} + v_b * m_b[/tex]
Here [tex]v_b[/tex] is the velocity of the bullet emerging from the first block
and [tex]u__{{B_1}}}[/tex] is zero because initial the first block was at rest
So
[tex]0.00616 * 342 + 1.155* 0 = v_b * 0.00616 + 1.155 * 0.728 [/tex]
[tex]v_b = 206.5 \ m/s [/tex]
Considering the second block
Gnerally according to the law of momentum conservation
[tex]m_b * v_b + m__{{B_2}}} * u__{{B_2}}} = [m__{{B_2}}} +m_b] v[/tex]
Here [tex]u__{{B_2}}}[/tex] is zero because initial the second block was at rest
=> [tex]0.00616 * 206.5 + 1.517* 0= [1.517 +m_b] v [/tex]
=> [tex]0.00616 * 206.5 = [1.517 +0.00616] v [/tex]
=> [tex]v = 0.8351 \ m/s [/tex]
The kinetic energy of the bullet before collision is
[tex]K_b = \frac{1}{2} * m * u_b^2[/tex]
=> [tex]K_b = 0.5 * 0.00616 * 342^2[/tex]
=> [tex]K_b = 360.2 \ J [/tex]
The kinetic energy of the bullet after collision is
[tex]K_a = \frac{1}{2} * m * v^2[/tex]
=> [tex]K_a = 0.5 * 0.00616 * 0.8351^2[/tex]
=> [tex]K_a = 0.00214 \ J [/tex]
Generally the ratio of the kinetic energy is mathematically represented as
[tex]\frac{K_a}{K_b} = \frac{0.00214}{360.2 }[/tex]
=> [tex]\frac{K_a}{K_b} = \frac{0.00214}{360.2 }[/tex]
=> [tex]\frac{K_a}{K_b} = 5.94 11 *10^{-6}[/tex]
If you throw an object straight up into the air with an initial velocity of 42m/s. What is it’s velocity at the peak of its flight?
A. 42m/s
B. -42m/s
C. 9.8m/s
D. -9.8m/s
E. 0m/s
F. 0m/s2
G. None of these
A space vehicle is coasting at a constant velocity of 16.9 m/s in the y- direction relative to a space station. The pilot of the vehicle fires a RCS (reaction control system) thruster, which causes it to accelerate at 0.395 m/s^2 in the x direction. After 38.8 s, the pilot shuts off the RCS thruster. After the RCS thruster is turned off.
Find:
a. The magnitude.
b. The direction of the vehicle's velocity relative to the space station. Express the direction as an angle (in degrees) measured from the y- direction
Answer:
See attached file for the answer
what is the right way to sleep
Answer:
by lying down on a nice and soft quilted matress
A man driving a car traveling at 20 m/sec slams on the brakes and decelerates at 3.25
m/s^2. How far does the car travel before it stops?
Recall that
[tex]{v_f}^2-{v_i}^2=2a\Delta x[/tex]
where [tex]v_i[/tex] and [tex]v_f[/tex] are initial and final velocities, respectively; [tex]a[/tex] is acceleration; and [tex]\Delta x[/tex] is the net displacement, or distance if the object is moving in a single direction.
The car has initial speed 20 m/s and acceleration -3.25 m/s². It comes to a stop, so it has 0 final speed. Then
0² - (20 m/s)² = 2 (-3.25 m/s²) ∆x
∆x = (20 m/s)² / (7.5 m/s²) ≈ 53.3 m
Starting from rest, a car travels 18 meters as it accelerates uniformly for 3.0 seconds. What is the magnitude of
the car's acceleration?
Answer:
[tex]a=4\frac{m}{s^2}[/tex]
Explanation:
Hello.
In this case, for this uniformly accelerated motion in which the car starts from rest at 0 m/s and travels 18 m in 3.0 s, we can compute the acceleration by using the following equation:
[tex]x_f=x_0+v_0t+\frac{1}{2}at^2[/tex]
Whereas the final distance is 18 m, the initial distance is 0 m, the initial velocity is 0 m/s and the time is 3.0 s, that is why the acceleration turns out:
[tex]a=\frac{2(x_f-v_ot)}{t^2} =\frac{2(18m-0m/s*3.0s)}{(3.0s)^2}\\ \\a=4\frac{m}{s^2}[/tex]
Best regards.
Given the distance travelled and the time taken, the magnitude of the car's acceleration is 4m/s²
Given the data in the question;
Since the car starts from rest,
Initial velocity; [tex]u = 0m/s[/tex]Distance travelled; [tex]s = 18m[/tex]time taken; [tex]t = 3.0s[/tex]Acceleration; [tex]a = \ ?[/tex]
To determine the magnitude of the car's acceleration
We use the Second Equation of Motion:
[tex]s = ut + \frac{1}{2}at^2[/tex]
Where s is the speed, u is the initial velocity, a is the acceleration and t is the time.
We substitute our values into the equation and solve for "a"
[tex]18m = (0m/s\ * 3.0s) + (\frac{1}{2}\ *\ a\ *\ (3.0s)^2) \\\\18m = 4.5s^2 \ *\ a\\\\a = \frac{18m}{4.5s^2} \\\\a = 4 m/s^2[/tex]
Therefore, the magnitude of the car's acceleration is 4m/s²
Learn more: https://brainly.com/question/10428597
An object of mass 10kg is accelerated upward at 2 m/s2. What force is required
Answer:
The answer is 20 NExplanation:
The force acting on an object given the mass and acceleration we use the formula
force = mass × accelerationFrom the question
mass = 10kg
acceleration = 2 m/s²
We have
force = 10 × 2
We have the final answer as
20 NHope this helps you
A rocket is launched from a height of 3 m with an initial velocity of 15 m/s What is the maximum height of the rocket? When will this occur?
If no extra acceleration is added to the rocket, then its velocity at time t is
v = 15 m/s - g t
where g = 9.80 m/s² is the magnitude of the acceleration due to gravity.
Also, recall that
v² - u² = 2 a ∆x
where u is initial speed, v is final speed, a is acceleration, and ∆x is net displacement.
At the rocket's maximum height ∆x, the velocity is 0. So, the maximum height is
0² - (15 m/s)² = 2 (-g) ∆x
∆x = (15 m/s)² / (2 * (9.80 m/s²)) ≈ 11.48 m
But this assumes the rocket is launched from the ground. We're given that the rocket is launced from 3 m above the ground, so we need to add this to the height above. So the maximum height is closer to 14.48 m.
As mentioned before, this happens when vertical velocity is 0:
0 = 15 m/s - g t
t = (15 m/s) / (9.80 m/s²) ≈ 1.53 s
astronaut A can cover 10 meters per minute walking with the heavy shovel. What does
this sentence describe?
a) None of these things
b) Both speed and velocity
C) The velocity of the astronaut
d) The speed of the astronaut
Answer:
d) The speed of the astronaut
Explanation:
The sentence describes the speed of the astronaut. This speed value is 10meters per minute.
Now let us understand why;
Speed is the distance divided by time. It is a scalar quantity without regard for direction but it has magnitude. The value 10meters per minute clearly shows this instance. We do not know the direction the astronaut is moving towards. Velocity, like speed is the displacement of a body with time. It is a vector quantity and it shows the direction of motion. For example, 10m/s due west is a velocity value because we know the direction.Therefore, since there is no directional sense, the value indicates speed.
The given sentence describes the speed of the astronaut. Hence, option (d) is correct.
Given data:
The distance covered by the astronaut A is, d = 10 m.
the time interval is, t = 1 min = 60 s.
Clearly, the given sentence describes the speed of the astronaut. This speed value is 10 meters per minute. This is because of following reason:
Speed is the distance divided by time. It is a scalar quantity without regard for direction but it has magnitude. The value 10meters per minute clearly shows this instance. We do not know the direction the astronaut is moving towards. Velocity, like speed is the displacement of a body with time. It is a vector quantity and it shows the direction of motion. For example, 10m/s due west is a velocity value because we know the direction.Thus, we can conclude that the given sentence describes the speed of the astronaut. Hence, option (d) is correct.
Learn more about the speed here:
https://brainly.com/question/22610586
Q.9) Consider a plot of the displacement (x) as a function of the applied force (F) for an ideal elastic spring as
shown, see figure. The slope of the curve would be
A) the acceleration due to gravity.
B) the reciprocal of the acceleration of gravity.
C) the mass of the object attached to the spring.
D) the reciprocal of the spring's constant.
Answer:
Option (D).
Explanation:
For an ideal spring, the force is given in terms of displacement as follows :
F=-kx
[tex]x=\dfrac{-F}{k}\\\\\text{or}\\\\x=\dfrac{-1}{k}F[/tex]...(1)
Where,
x is displacement in spring i.e. compression or stretching
k is spring constant of the spring
-ve sign shows that the force exerted by the spring is in opposite direction of the spring's displacement.
The equation of a line is : y=mx+c, m is slope
From equation (1)
Slope = 1/k
or
Slope = reciprocal of the spring's constant.
It would mean that the slope of the curve represents the reciprocal of the spring's constant.
Using the spring constant and displacement relation, the slope of the curve would be the reciprocal of the spring's constant.
Using the Force constant relation :
F = keF = Force ; k = spring constant ; e = extension
F = kxMaking the x the subject of the formula :
x = F/kThe slope, which is the spring constant can be expressed as ;
x = 1/k × FHence, the slope is the reciprocal of the spring constant.
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