Answers
Answer:
1) a. 52.41 m/s
b. The skier will be going 15.35 m/s slower
2) 103.68 m
3) 35,127 J
4) a. 88.825 kJ
(b) 16.36 %
5) 3,071.12 J
Explanation:
1) a. The given height of the hill, h = 140.0 m
The mass of the skier at the top of the hill, m = 85.0 kg
The acceleration due to gravity, g = 9.81 m/s²
The initial potential energy, P.E of the skier = m×g×h = 85.0×140.0×9.81 = 116739 J
From the principle of conservation of energy, we have;
The potential energy, P.E. lost = The gain in kinetic energy, K.E.
m×g×h = 1/2×m×v²
116739 J = 1/2×85.0×v²
v² = 116739/(1/2*85.0)= 2746.8 m²/s²
v = √(2746.8 m²/s²) = 52.41 m/s
b. From 70 m up, we have;
The initial potential energy, P.E., of the skier is now = 85.0×70×9.81 = 58,369.5 J
The potential energy, P.E. lost = The gain in kinetic energy, K.E.
58,369.5 J = 1/2×85.0×v²
v² = 58,369.5/(1/2*85.0) = 1373.4 m²/s²
v = 37.06 m/s
The skier will be going 52.41 - 37.06 = 15.35 m/s slower
The skier will be going 15.35 m/s slower
2) From the principle of conservation of energy, the amount of work done (energy used) = The (potential) energy gained by the load
The amount of work done by the electric hoist = 356,000 J
The mass of the load = 350.0 kg
The height to which the load is raised = h
The potential energy gained by the load = m×g×h = 350.0×9.81×h
356,000 J = 350.0×9.81×h
h = 356,000/(350.0*9.81) = 103.68 m
The height to which the load is lifted= 103.68 m
3) The initial potential energy of the roller coaster cart = 600*35.0*9.81 = 206010 J
The final potential energy = 600*28.0*9.81= 164808 J
The velocity at point 3 = 4.5 m/s
The kinetic energy at point 3 = 1/2*600*4.5^2 = 6075 J
The total energy at point 3 = 164808 + 6075 = 170,883 J
The energy loss = The initial potential energy at point 1 - Total energy at point 3
The energy loss = 206010 - 170,883 = 35,127 J
The heat energy due to friction that must have been produced between points 1 and 3 = 35,127 J
4) a. The heat energy absorbed = mass × specific heat capacity for water, [tex]C_{water}[/tex] × Temperature change
The mass of the water = 2.5×10² g = 0.25 kg
[tex]C_{water}[/tex] = 4,180 J/(kg·°C)
Initial temperature = 10.0°C
Final temperature = 95°C
The temperature change = 95.0°C - 10.0°C = 85.0°C
The heat energy absorbed = 0.25*4,180* 85 = 88,825 J = 88.825 kJ
(b) The percentage efficiency = (Heat absorbed/(Heat supplied)) × 100
The heat supplied = 543 kJ
The efficiency = (88.825/543) × 100 = 16.36 %
5) The mass of the box = 115 kg
Force acting on the rope = 255 N
The angle of inclination of the force to the horizontal = 24.5°
The distance the box is displaced = 15.0 m to the right
The work done = Force applied × distance moved in the direction of the force
The work done = Force applied × distance moved in the direction of the force
Given that the load moves a distance 15.0 m to the right,we have;
The component of the force acting in the direction of the movement of the load (to the right) is 225 × cos(24.5°) = 204.74 N
The work done = 204.7*15 = 3071.12 J
The amount of work done = 3,071.12 J
Related Questions
Which force is there between an ice skate and the ice
Answers
At the same time, if there were no friction at all on ice, skating would be impossible, because it is the friction between the skate and the ice when a skater pushes off that starts the motion to begin with. And friction is also what allows a skater to ever come to a stop.
the velocity is always _____ to the line of a circle
Answers
Answer:
tangent
Explanation:
hope it helps
Answer:
the answer is tangent
Explanation:
tangent means a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.
hope this helps please like and heart this answer and give 5 stars and brainliest pls i beg u thx!!! : )
Whats a scientific clame?
Answers
Answer:
A claim made by scientists backed up with evidence and research!
Explanation:
Hope this helped! :)
A 20.0 Ohm and 60.0 Ohm resistor
are connected in series to a 9.00 V
battery. What is the voltage drop
across the 20.0 Ohm resistor?
(Hint: How much current flows
across it?)
(Unit = V)
Answers
Answer:
2.25 V
Explanation:
The equivalent resistance is:
R = 20.0 Ω + 60.0 Ω
R = 80.0 Ω
The current is:
V = IR
9.00 V = I (80.0 Ω)
I = 0.1125 A
The voltage drop across the 20.0 Ω resistor is:
V = IR
V = (0.1125 A) (20.0 Ω)
V = 2.25 V
differentiate between earthworm and housefly
Answers
Answer:
Earthworm lives in the soil, eats the soil which has organic matter such as decaying vegetation or leaves and crawls. While housefly lives in dirty places, feeds on faeces and flies.
Hope I get a brainliest answer.
Na (g) + 2HCl (g) -> H2 (g) + 2NaCl (s) is a balanced equation? True or false?
Answers
Answer:
False, the given equation is not balanced.
Explanation:
The given equation is:
Na(g) + 2HCl(g) → H₂(g) + 2NaCl(s)
And it is not balanced, the number of atoms of Na is not the same on both sides of the equation.
The balanced equation is:
2Na(g) + 2HCl(g) → H₂(g) + 2NaCl(s)
Now, the given equation is balanced, we have the same number of atoms on both sides of the equation.
Therefore, the answer is false, the given equation is not balanced.
I hope it helps you!
Please help ASAP. A car engine with a mass of 1750 kg can exert 215 000 W. a) How long will it take the car to reach 95.0 km/h if the car is 100% efficient? b) If it actually takes the car 6.5 s to reach 95.0 km/h, what is the efficiency of the car?
Answers
✔ First step : calculate the kinetic energy that this car requires to reach 95 km/h
95/ 3,6 ≈ 26,4 m/s
Ec = ½ m x V²
With Ec in J; m in kg; and V in m/s
Ec = ½ 1750 x 26,4² Ec ≈ 610 000 J✔ Knowing that the car has a p power of 215,000 W, so :
T = E/P
T = 610 000/215 000 T ≈ 2.8 s The car takes 2.8 s to reach 95 km/h QUESTION②)N = 2,8/6,5 x 100 = 43.07
The car efficiency is 43 %Bruno the bat flies at a speed of 0.5 m/s in circle of radius 1 m. What is his acceleration?
Very urgent pls help
Answers
Answer:
Acceleration is 0.25m/s^2
Explanation:
Given the following :
Speed = 0.5m/s
Radius(r) of circle = 1m
Acceleration round a circular path is given as :
a = v^2 / r
Where
a = acceleration of the body
v = speed / velocity
r = radius
Therefore,
a = v^2 / r
a = (0.5)^2 / 1
a = 0.25m/s^2
A rocket moves through empty space in a straight line with constant speed. It is very far from any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is
Answers
Answer:
analysis the force is zero
Explanation:
Let's apply Newton's second law
F = m a
In this equation we see that the force is directly related to the acceleration, as they indicate that the rocket is far from any planet or star has no force applied to it, therefore they also relate it to zero.
Change we can analyze the exercise with Newton's first law, which indicates that an object maintains its constant speed in a straight line has no forces applied to it.
In either analysis the force is zero
Three resistors, A, B, and C, are connected in parallel and attached to a battery, with the resistance of A being the smallest and the resistance of C the greatest. Which resistor carries the highest current?
Answers
Answer:
Resistor A
Explanation:
Resistors A, B and C are connected in parallel to a battery of voltage represented by V.
Since they are in parallel, the same voltage, V, passes across the three of them.
And from Ohm's law, the voltage (V) through a resistor is the product of the current (I) flowing through it and the resistance (R) of the resistor. i.e
V = I x R
=> I = [tex]\frac{V}{R}[/tex]
Therefore, assuming the values of the resistances of resistors A, B and C are A, B and C respectively,
(i) the current, [tex]I_{A}[/tex] through A is
[tex]I_{A}[/tex] = [tex]\frac{V}{A}[/tex]
(ii) the current, [tex]I_{B}[/tex] through B is
[tex]I_{B}[/tex] = [tex]\frac{V}{B}[/tex]
(iii) the current, [tex]I_{C}[/tex] through C is
[tex]I_{C}[/tex] = [tex]\frac{V}{C}[/tex]
From the foregoing, it can be deduced that the current is inversely proportional to the resistance. Therefore, the higher the resistance, the lower the current. Consequential of this, the resistor that carries the highest current is the one with the smallest resistance, which is A
Resistor A
Given:
Resistors A, B and C are connected in parallel to a battery of voltage represented by V.
Since they are in parallel, the same voltage, V, passes across the three of them.
Ohm's law:
It states that voltage (V) through a resistor is the product of the current (I) flowing through it and the resistance (R) of the resistor. i.e.
V = I x R
⇒ I = V/R
Therefore, assuming the values of the resistances of resistors A, B and C are A, B and C respectively,
(i) the current, through A is
[tex]I_A=\frac{V}{A}[/tex]
(ii) the current, through B is
[tex]I_B=\frac{V}{B}[/tex]
(iii) the current, through C is
[tex]I_C=\frac{V}{C}[/tex]
From the Ohm's law we can say that the current is inversely proportional to the resistance.
Therefore, higher the resistance, the lower is the current.
It is given that resistance of A being the smallest, thus is will carries the highest current.
Learn more:
brainly.com/question/16014555
the velocity is always _____ to the line of a circle
Answers
Answer:
The velocity is always tangent to the line of a circle .
Explanation:
When an object moves in a circular path, its motion is called the circular motion. The speed of the object is constant at each and every point in such motion while the velocity changes due to change in direction.
In a circular motion, the direction of velocity is always tangent to the circle. At each and every point, its direction is found tangentially.
A force produces an acceleration of 5 ms
when applied on a body of mass 4 kg. The
magnitude of the force applied is
Answers
F = m • a (I. Newton)
F = (4 kg) x (5 m/s^2)
F = 20 Newtons
You release a pendulum of mass 1 kg from a height of 0.75 m. If there is no air resistance, how fast is the pendulum going when it reaches the bottom
Answers
Explanation:
PE = KE
mgh = ½ mv²
v = √(2gh)
v = √(2 × 9.8 m/s² × 0.75 m)
v = 3.83 m/s
Round the numbers that follow to three significant figures and express the result in standard exponential notation: (a) 143,700; (b) 0.09750; (c) 890,000; (d) 6,764E4; (e) 33,987.22; (f) - 6.5559.
Answers
Explanation:
Non-zero digits are always significant.
Zeros between significant digits are also significant.
Trailing zeros are significant only after a decimal point.
(a) 143,700
First, write in scientific notation.
1.437×10⁵
Now, round to 3 significant figures.
1.44×10⁵
(b) 0.09750
= 9.750×10⁻²
= 9.75×10⁻²
(c) 890,000
= 8.9×10⁵
= 8.90×10⁵
(d) 6,764×10⁴
= 6.764×10⁷
= 6.76×10⁷
(e) 33,987.22
= 3.398722×10⁴
= 3.40×10⁴
(f) -6.5559
= -6.5559×10⁰
= -6.56×10⁰
The scientific notation and round-off of the number are given below:-
(a) 143,700 = 1.44×10⁵
(b) 0.09750 = 9.75×10⁻²
(c) 890,000 = 8.90×10⁵
(d) 6,764×10⁴ = 6.76×10⁷
(e) 33,987.22 = 3.40×10⁴
(f) -6.5559 = -6.56×10⁰
What is a scientific notation?Numbers that are either too large or too little to be conveniently stated in decimal form can be expressed using scientific notation. It may be called scientific form.
When a number is written using only the digits of the number, that is considered standard notation. Since words are not used in conventional number notation, this is the way that numbers are typically written.
Non-zero digits are always significant. Zeros between significant digits are also significant.
Trailing zeros are significant only after a decimal point.
(a) 143,700
First, write in scientific notation.
1.437×10⁵
Now, round to 3 significant figures.
1.44×10⁵
(b) 0.09750
= 9.750×10⁻²
= 9.75×10⁻²
(c) 890,000
= 8.9×10⁵
= 8.90×10⁵
(d) 6,764×10⁴
= 6.764×10⁷
= 6.76×10⁷
(e) 33,987.22
= 3.398722×10⁴
= 3.40×10⁴
(f) -6.5559
= -6.5559×10⁰
= -6.56×10⁰
Therefore, the numbers can be written in the scientific notations as above.
To know more about scientific notations follow
brainly.com/question/106363
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A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 newtons. What is the acceleration of the wagon?
Answers
Answer:
0.2 m/s²Explanation:
Given,
Mass ( m ) = 10 kg
Force ( f ) = 2 Newtons
Acceleration ( a ) = ?
Now, let's find the acceleration :
We know that,
[tex]f = ma[/tex]
Plug the values
[tex]2 = 10a[/tex]
Swap the sides of the equation
[tex]10a = 2[/tex]
Divide both sides of the equation by 10
[tex] \frac{10a}{10} = \frac{2}{10} [/tex]
Calculate
[tex]a = 0.2 \: {metre \: per \: second \: }^{2} [/tex]
Hope this helps...
Best regards!!
A truck is moving with a certain uniform velocity. It is accelerated uniformly by 0.75 m/s^2. After 20 seconds , the velocity becomes 72km/h.Find the initial velocity
Answers
Answer:
Vi = 5 m/s
Explanation:
let (a) acceleration = 0.75 m/s²
(t) time = 20 seconds
Vf = final velocity = 72 km/hr (convert to m/s to units consistency = 20 m/s)
find Initial velocity (Vi)
Vf - Vi
a = -----------
t
Vi = Vf - (a * t) = 20 - (0.75 * 20)
Vi = 5 m/s
CAN YOU HELP ME IN THE FOLLOWING EQUATION THE SPEED IS V = A + BT. DETERMINE THE DIMENSIONS OF A AND B
Answers
Answer:
A = [m/s]
B = [m/s²]
Explanation:
Assuming that V has SI units of m/s, then A and BT must also have units of m/s.
A = [m/s]
BT = [m/s]
Since T has SI units of s:
B [s] = [m/s]
B = [m/s²]
What includes a distance and a direction? A. Acceleration B. Speed C. Displacement D. Velocity
Answers
Answer:displacement
Explanation:
A student focussed the image of a candle flame on a white screen using a convex lens. He noted down the position of candle, screen and the lens as under Position of candle = 12.0 cm Position of convex lens = 50.0 cm Position of the screen = 88.0 cm i.What is the focal length of the convex lens? ii. Where will the image be formed if he shifts the candle towards the lens at a position of 31.0 cm? iii. What will be the nature of the image formed if he further shifts the candle towards the lens? iv. Draw a ray diagram to show the formation of the image in case (iii) as said above.
Answers
Answer:
Explanation:
Object distance = distance between object and lens
u = 50 - 12 = 38 cm
image distance v = 88 - 50 = 38 cm
i )
using lens formula
1 / v - 1 / u = 1 / f
1 / 38 - 1 / - 38 = 1/f
2 / 38 = 1 / f
f = 19 cm
ii ) So object is placed at 2 f or at the center of curvature of the lens .
If object distance is changed to 50 - 31 = 19 cm
using lens formula
1 / v - 1 / u = 1 / f
1 / v + 1 / 19 = 1/19
1 / v = 0
v = infinity
It is so because now the object is placed at the focal distance
iii )
If object further shifts towards the lens , then virtual image of object will be formed behind the lens which will be larger than object .
Trivikram jogs from one end of corniche to its other end on a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back on same track in another 1 minute. What is his average speed and velocity
Answers
Answer:
average speed = 1.73m/s
average velocity = 3.33m/s
Explanation:
we'll find the average speed first
average speed = total distance / total time
his total distance is 300m + 100m
= 400m
and total time should be taken in seconds as you know
((2×60)+50) + 60s
= 230s
so let's divide,
400m/230s
1.73 m/s
next, mean velocity
that is,
mean velocity = final- initial displacement/time
we have to note displacement ( this is the distance between the initial point to final point) here
the displacement is 300-100
so, 200m
we already calculated total time
but that cant be taken here
230 - 170
is the original time to travel 200m
that is, 60s
so we divide
200/60
3.33m/s
Suppose a piece of food is on the edge of a rotating microwave oven plate. Does it experience nonzero tangential acceleration, centripetal acceleration, or both when: (a) The plate starts to spin
Answers
Answer:
the only acceleration it has is radial (centripetal)
Explanation:
The microwaves plate rotates at a constant speed after a very short period of acceleration.
Therefore we can apply Newton's second law
F = m a
where the acceleration is centripetal
a = v2 / r = w2 r
therefore as it rotates constant speed it cannot have a tangential acceleration since it changes the modulus of the speed.
Consequently the only acceleration it has is radial (centripetal)
If two people are running at the same speed in the same direction. One person is one meter ahead of the other. The person in front throws a ball to the person slightly behind. As seen by an observer at rest on the ground, is it possible that the ball looks as if it was thrown forward
Answers
Answer:yes
Explanation:
calculate the magnitude of the electric field intensity in vacuum at a distance of 20 cm from a charge of 5 * 10 raise to power - 3 column
Answers
Answer:
1.1259*10^9 Newton per Columb
Explanation:
the magnitude of the electric field intensity can be calculated using the expresion below;
E=Kq/r^2
Where k= constant
q= electric charge
r=distance= 2cm= 20*10^-2m( we convert to m for unit consistency
:,K=59*10^9 Columb
If we substitute the value into above formula we have
E=(9*10^9)*(5*10^-3)/(20*10^-2)^2
=1.1259*10^9 Newton per Columb
Therefore,the magnitude of the electric field intensity in vacuum at a distance of 20 cm is 1.1259*10^9 Newton per Columb
Please answer this question
Answers
Explanation:
m = kg. v=m/s. g=m/s^2. h= m
>>1/2mv^2=mgh
>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m
>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m>>kg m^2/s^2=kg m^2/s^2 the fraction 1/2 won't be able to make any changes to to the dimensional expression of energy i.e half of energy is still energy therefore you can neglect the number .
>>kg m^2/s^2=kg m^2/s^2
>>J= J
Can someone please help me?
An alien spaceship is 650 m above the ground and moving at a constant velocity of 175 m/s upwards.
How high above the ground is the ship after 5 seconds?
Answers
Answer:
1525 meters above ground
Explanation:
So to do this you will need to write this in slope intercept form or [tex]y=mx+b[/tex]. So 650 would be the b, 175 would be the m, and the x would be 5 so the equation would be [tex]y=175(5)+650[/tex] so if you solve or simplify the equation you will get 1525 meters above the ground and that would be our final answer.
Spring balance measures weight, not the mass of a body.
Answers
Answer:
That is true and is easily explained by the next equation:
W= m*g
where
W= Weight
m=mass
g= gravitational acceleration
so, if you use a spring balance in another planet with a different gravitational acceleration the measured weight will be different.
The large-scale distribution of galaxies in the universe reveals Group of answer choices a smooth, continuous, and homogenous arrangement of clusters large voids, with most of the galaxies lying in filaments and sheets a large supercluster at the center of universe a central void with walls of galaxies at the edge of the universe
Answers
Question
The large-scale distribution of galaxies in the universe reveals
A) a smooth, continuous, and homogenous arrangement of clusters
B) large voids, with most of the galaxies lying in filaments and sheets a large supercluster at the center of the universe
C) a central void with walls of galaxies at the edge of the universe
Group of answer choices
Answer:
The correct answer is B)
Explanation:
The universe is arranged in a filamentary structure. Filamentary structures are very large. They are the largest kind of structures in the universe and comprise mostly of galaxies that are held together by gravity.
The structures found within Galaxy filaments have thread-like qualities spanning 52 to 78.7 megaparsecs h⁻¹ in lenght.
Other phenomena associated with the nature fo the universe is the existence of void spaces.
Cheers!
Answer the following three questions in complete sentences. 1. How much does the earth weigh? 2. How far away is the sun? 3. What is a black hole?
Answers
Answer: find the answer in the explanation.
Explanation:
1.) The weight of the earth can be calculated and estimated by the physicist by considering the mass of the earth and the knowlegde of gravity.
If the mass of the earth is considered to be 6 × 10^24 kg. Then with Physics formula and some mathematical techniques, we can conclude that the weight of the earth is approximately equal to 6 × 10^25 N.
2.) The distance of the sun to the earth is approximately 1.5 × 10^8 km. This measure is the distance from the surface of the earth to the sun.
3.) The black hole is approximately the size of the earth of very large gravitational field strength. It is a region of space of enormous gravity where no particular object can escape from it. Even electromagnetic radiation or light cannot escape from it.
Answer:
The Earth weighs 5.972 × 10^24 kg
The Sun is 94.022 million miles away.
A black hole is is a region of spacetime where gravity is so strong that nothing, no particles or even electromagnetic radiation such as light can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.
I hope this helps!! :)
Question 21 of 25
Barry slides across an icy pond. The coefficient of kinetic friction between his
shoes and the ice is 0.15. If his mass is 83 kg, what is the force of friction
acting on him
O A 352 N
O B. 122 N
C. 1150 N
O D. 813N
Answers
Answer:
B. 122N
Explanation:
f = 0.15 x 83 x 9.8 = 122.01
f = 122N
a boy has a mass of 80kg on earth where g= 10N/kg a) what is his mass on the moon b ) find his weight on the moon ( g= 10N/kg)
Answers
Explanation:
mass on moon is also 80kg because it doesn't differed according to place.
I think we can't calculate weight because there is no gravity in moon
Answer 80kg
Explanation Mass is constant in every corner of universe. It's better if u have asked about weight on moon. It is same in both earth and moon.