Answer:
W
Explanation:
The unit for Power which is (Volt X Current) is Watts. and the symbol for Watts is W.
To a stationary observer, a bus moves south with a speed of 12 m/s. A man
inside walks toward the back of the bus with a speed of 0.5 m/s relative to
the bus. What is the velocity of the man according to a stationary observer?
A. 11 m/s south
B. 12.5 m/s south
C. 11.5 m/s south
D. 0.5 m/s south
ANSWER
C 11.5 m/s
EXPLANATION
Answer:
11.5m/s south
Explanation:
Online classes
Y=5sin (3x -4t)
Cdculate the wavelength frequency and period.
Pls answer and explanation with formula
explanation
the general form of wave equation is
y=Asin(kx-wt)
we have
y=5sin(3x-4t)
hence the angular frequency
w= 4s^-1
the frequency
f=w/2 pi
f=4/2 pi
f=4/2*3.14
f=0.64 hz
the period
T=1/f
T=1/0.64
T=1.5625=1.6
the wavelength
k=2 pi/lambda
lambda=2 pi/k
k=3
so
lambda=2*3.14/3
lambda=2.09
if my answer is right then mark me brainlist
This is a question on my physics test :)
Can any1 help me? if you can, please give an explanation
Answer:
119.6 J/Kg°C
Explanation:
Data obtained from the question include:
Mass of substance (ms) = 170 g
Initial temperature of substance (Ts) = 120 °C
Volume of water = 200 mL
Initial temperature of water (Ts) = 10 °C
Temperature of the mixture (T2) = 12.6 °C
Density of water = 1 g/mL
Specific heat capacity of water (Cw) = 4200J/Kg°C
Specific heat capacity of substance (Cs) =..?
Next, we shall determine the mass of water. This can be obtained as follow:
Volume of water = 200 mL
Density of water = 1 g/mL
Mass of water =..?
Density = mass /volume
1 = mass /200
Cross multiply
Mass of water = 1 x 200
Mass of water = 200 g
Convert 200 g of water to Kg
Mass of water = 200/1000 0.2 Kg
Mass of water = 0.2 Kg
Now, we obtained the specific heat capacity of the substance using the following formula:
MwCw(T2 – Tw) + MsCs(T2 – Ts) = 0
Mass of water = 0.2 Kg
Initial temperature of water (Ts) = 10 °C
Specific heat capacity of water (Cw) = 4200J/Kg°C
Temperature of the mixture (T2) = 12.6 °C
Mass of substance (ms) = 170 g = 170/1000 = 0.17 Kg
Initial temperature of substance (Ts) = 120 °C
Specific heat capacity of substance (Cs) =..?
MwCw(T2 – Tw) + MsCs(T2 – Ts) = 0
0.2× 4200(12.6 – 10) + 0.17×Cs×(12.6 – 120) = 0
840(2.6) + 0.17Cs(– 107.4) = 0
2184 – 18.258Cs = 0
Rearrange
2184 = 18.258Cs
Divide both side by the coefficient of Cs i.e 18258
Cs = 2184/18.258
Cs = 119.6 J/Kg°C
Therefore, the specific heat capacity of the substance is 119.6 J/Kg°C
Which is one piece of evidence of seafloor spreading?
a. fossil material
b. continent material
c. drilled core samples
d. ocean water samples
Answer:
A. Continent material
Explanation:
Eruptions of molten material, which results in continent material is a piece of evidence of seafloor spreading.
Continent material is one piece of evidence of seafloor spreading. Option b is correct.
What is seafloor spreading?Seafloor spread is a phenomenon that happens along mid-ocean ridges, when new oceanic crust is generated by volcanic activity and then progressively travels away from the ridge.
The geological activity of seafloor spreading occurs when tectonic plates split apart.
Continent material is one piece of evidence of seafloor spreading.
Hence, option b is correct.
To learn more about the seafloor spreading, refer to the link;
https://brainly.com/question/15122129
#SPJ2
A ball is launched from the ground with a horizontal speed of 30 m/s and a vertical speed of 30 m/s. What far vertically will it travel before hiting the ground A. 40 m B. 30 m C. 60 m D. 50 m
Answer:
First, let's think in the vertical problem:
The acceleration will be the gravitational acceleration:
g = 9.8 m/s^2
a = -9.8 m/s^2
For the velocity, we integrate over time:
v(t) = (-9.8 m/s^2)*t + v0
Where v0 is the initial velocity, in this case v0 = 30m/s.
v(t) = (-9.8 m/s^2)*t + 30m/s
Now, for the position we integrate again over time, and get:
P(t) = (1/2)*(-9.8 m/s^2)*t^2 + 30m/s*t + p0
Where p0 is the initial position, as the ball is launched from the ground, we can use p0 = 0m
p(t) = (-4.9m/s^2)*t^2 + 30m/s*t
Now, the maximum vertical height is reached when:
v(t) = 0m/s = -9.8m/s^2*t + 30m/s
t = 30m/s/9.8m/s^2 = 3.06s
Now we can evaluate the vertical position in t = 3.06s
p(3.06s) = (-4.9m/s^2)*(3.06)^2 + 30m/s*3.06 = 62m
So, rounding down, the correct option is: C. 60 m
Proved that
V = u+at
Answer:
[tex]\sf Proof \ below[/tex]
Explanation:
We know that acceleration is change in velocity over time.
[tex]\sf a=\frac{\triangle v}{t}[/tex]
[tex]\sf a=\frac{v-u}{t}[/tex]
v is the final velocity and u is the initial velocity.
Solve for v.
Multiply both sides by t.
[tex]\sf at=v-u[/tex]
Add u to both sides.
[tex]\sf at + u=v[/tex]
Answer:
Acceleration = v-u/t when we flip -u and t to right hand side
then -u changes to plus and denominator t changes to numerator
then then this equations becomes v=u+at
Explanation:
Which of the following scientists proposed the theories of relativity?
A. Galileo Galilei
B. Johannes Kepler
C. Albert Einstein
D. Sir Isaac Newton
Answer:
c) Albert Einstein,
Explanation:
in his theory of special relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels.
hope this helped
-lvr
When the current in a toroidal solenoid is changing at a rate of 0.0260 A/s, the magnitude of the induced emf is 12.2 mV. When the current equals 1.40 A, the average flux through each turn of the solenoid is 0.00308 Wb. How many turns does the solenoid have?
Answer:
The solenoid has 213 turns.
Explanation:
The number of the solenoid's turns (N) can be found as follows:
[tex] N = \frac{L*I}{\phi_{B}} [/tex] (1)
Where:
L: is the self-inductance of the solenoid
I: is the current = 1.40 A
[tex]\phi_{B}[/tex]: is the magnetic flux = 0.00308 Wb
The self-inductance of the solenoid (L) is:
[tex] L = \frac{|\epsilon|}{|dI/dt|} [/tex] (2)
Where:
ε: is the induced emf = 12.2x10⁻³ V
dI/dt: is the rate changing of the current = 0.0260 A/s
By entering equation (2) into (1) we can find the number of turns:
[tex] N = \frac{|\epsilon|*I}{\phi_{B}|dI/dt|} = \frac{12.2 \cdot 10^{-3} V*1.40 A}{0.00308 Wb*0.0260 A/s} = 213 [/tex]
Therefore, the solenoid has 213 turns.
I hope it helps you!
Click this link to view O*NET Skills section for Electrical Engineers. Note that common skills are listed toward the top and less common skills are listed toward the bottom. According to O*NET, what are some common skills Electrical Engineers need?
Explanation:
O*NET stands for Occupational Network and it is an online platform for job seekers around the world who are searching for jobs. This platforms provides the job information along with the required qualities, education background, skill sets, etc.
The most common skill sets that are required for an electrical engineers are
1. Analytical skills
2. Monitoring and active learning
3. Decision making
4. Able to manage the personal resources
5. Time management.
6. Should have knowledge about different software.
A rocket is launched vertically from the ground with an initial velocity of 64. Write a quadratic function that shows the height, in feet, of the rocket t seconds after it was launched.
Answer:
y = 64t − 16t²
Explanation:
y = y₀ + v₀ t + ½ at²
y = 0 + 64 t + ½ (-32) t²
y = 64t − 16t²
A mobile starts and travels 225 m with an acceleration of (- 3.5i + 4.5j) 2 along a rectilinear path. Determine:
a) The time spent
b) The final speed
c) The average speed I hope you can help me.
Answer:
a) 8.89 s
b) 50.6 m/s
c) 25.3 m/s
Explanation:
d = 225 m
v₀ = 0 m/s
a = (-3.5i + 4.5j) m/s²
First, find the magnitude of the acceleration.
a = √((-3.5)² + (4.5)²) m/s²
a = 5.7 m/s²
a) Find t
Δx = v₀ t + ½ at²
225 m = (0 m/s) t + ½ (5.7 m/s²) t²
t = 8.89 s
b) Find v
v² = v₀² + 2aΔx
v² = (0 m/s)² + 2 (5.7 m/s²) (225 m)
v = 50.6 m/s
c) Find v_avg
v_avg = Δx / t
v_avg = 225 m / 8.89 s
v_avg = 25.3 m/s
Or, for constant acceleration:
v_avg = (v₀ + v) / 2
v_avg = (0 m/s + 50.6 m/s) / 2
v_avg = 25.3 m/s
Calculate the gravitational acceleration of a satellite that is in orbit at a distance of 1.0 x 10^8 meters from the center of the Earth (Mass of Earth is 6.0 × 10^24).
Answer:
[tex]g=0.035\ m/s^2[/tex]
Explanation:
Given that,
Mass of Earth, [tex]m=6\times 10^{24}\ kg[/tex]
We need to find the gravitational acceleration of a satellite that is in orbit at a distance of [tex]10^8\ m[/tex] from the center of the Earth.
Radius of earth is 6,371 km
The formula used to find the gravitational acceleration at a distance is given by :
[tex]g=\dfrac{Gm}{R^2}[/tex]
R = r+d
[tex]g=\dfrac{6.67\times 10^{-11}\times 6\times 10^{24}}{(10^8+6371\times 10^3)^2}\\\\g=0.035\ m/s^2[/tex]
So, the gravitational acceleration is [tex]0.035\ m/s^2[/tex].
A scientist wants to measure the relationship between humidity in the
summer and the number of home runs in baseball. Which of the following is a
testable question about this topic?
A. Are home runs more exciting during the summer?
O B. Should fans like the players who hit the most home runs?
O C. Are home runs more fun to watch than normal hits?
D. Are there more home runs during the more humid months of the
summer?
Answer:
D
Explanation:
The most suitable testable question. in this case, would be that 'are there more home runs during the more humid months of the summer?'
Since the aim of the investigation is to find the relationship between humidity and the number of home runs, measuring the number of home runs during the more humid months in the summer and comparing the data to the number of home runs during the less humid months in the same summer would provide the answer.
Only option D raises a valid question that is relevant to the aim of the investigation.
A hollow circular shaft made of 304 stainless steel uniformly tapers from an outer diameter of 3.0 cm to an outer diameter of 4.0 cm over a length of 2 meters. The inner diameter of 1.0 cm is constant over the length of the shaft. The shaft is subjected to an applied torque of 500 Nm. Determine the maximum shear stress in the shaft.
Answer:
maximum shear stress = τ(max) = 95.49 × 10⁶N/m²
Explanation:
given
outer diameter at one end(D₁) = 3.0cm
outer diameter at the other end(D₂) = 4.0cm
inner diameter(d₁) = 1.0cm
torque applied(T) = 500Nm
maximum shear stress will occur at lower outer diameter
the formula is τ/r = T/J
τ= T × r/J
where r is radius
T is the torque
J is the polar 2nd M of area
attached is the calculation of the question
why is string a good force measurer?
Answer:
tension is how much force is being exerted on each end of the string, whereas length is how long the string is. So assuming that the string has finite mass, then the tension on the string should increase proportionally to the string according to Newton's law f=ma.
Explanation:
Salt compounds are commonly used to melt ice that forms on sidewalks in the winter. A common chemical that is used to melt sidewalk ice is calcium chloride, CaCl2(s). When calcium chloride dissolves into solution is releases thermal energy which aides in melting
the ice.
The molar mass of water is 18.02 g/mol
The thermal energy, in kilojoules (kJ) that must be released from the calcium chloride,
CaCl2(s), to melt 10.0 kg of ice, expressed in scientific notation is a.bc x 104 k).
46
55
The values of a, b, c, and d.
Answer:
The values of a, b, c and d are
a = 3, b = 3, c = 4 and d = 3
Explanation:
The quantity of heat needed to melt the ice is given by Q = mL where m = mass of ice and L = latent heat of fusion of ice = 334 kJ/kg. This quanity of heat is also the thermal energy needed to be released by the calcium chloride, CaCl₂
Now, the mass of ice = 10 kg. So,
Q = mL
Q = 10 kg × 334 kJ/kg
Q = 3340 kJ
In scientific notation,
Q = 3.34 × 10³ kJ
So the thermal energy needed to be released by the calcium chloride is 3.34 × 10³ kJ
Comparing Q = 3.34 × 10³ kJ with a.bc × [tex]10^{d}[/tex] kJ
So, a = 3, b = 3, c = 4 and d = 3
The values of a, b, c and d are
a = 3, b = 3, c = 4 and d = 3
Which egg floated higher? Why do you think that happened?
Answer:
Generally, fresh eggs will lie on the bottom of the bowl of water. Eggs that tilt so that the large end is up are older, and eggs that float are rotten.
Explanation:
Three children use the same skateboard. i) 20-30kg, ii) 30-40 kg iii) 40-50kg Which child can move the skateboard using the smallest pushing force? Justify your choice.
Answer:
i) 20-30 kg
Explanation:
The child with the smallest mass range of 20-30 kg will require the smallest force to move his skate board because he/she has a smaller inertia force to overcome. The mass of a body is the measure of the inertia forces of the body. The inertia force makes it difficult for a body at rest to start moving, and a body already in motion to stop moving.
When the children try to move the skateboard, they exert a force that is proportional to the product of their mass and the acceleration with which they start moving. This force must exceed their body's inertia force before they would start moving.
from
F = ma
where F is the force required
m is the mass
a is the acceleration
We can see that for the given mass ranges, the children with the larger mass range will require more force in order to move their skateboard. Consequently, the child with the smallest mass range will require the smallest pushing force to move his skate board.
Is the following nuclear reaction balanced?
Answer:
yes
Explanation:
How does increasing frequency affect the crests of a wave?
They get higher.
They get closer together.
They get lower.
They get farther apart.
Answer:
they get closer together
Explanation:
Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the surface of the door. One child pushes with a force of 17.5 N at a distance of 0.59 m from the hinges, and the second child pushes at a distance of 0.47 m.
What force must the second child exert to keep the door from moving? Assume friction is negligible.
Answer:
F₂ = 21.97 N
Explanation:
this is a rotational equilibrium exercise, let's write the formula
∑ τ = 0
F₁ d₁ - F₂ d₂ = 0
force F₁ is 17.5 N and its distance d₁ = 0.59m, the distance d₂ = 0.47m
F₂ = F₁ d₁ / d₂
F₂ = 17.5 0.59 / 0.47
F₂ = 21.97 N
Hydrogen fuel cells are used on the space shuttle to provide the shuttle with all of its electrical energy. Explain why fuel cells are used instead of batteries.
Answer:
Hydrogen used in fuel cells has the energy to weight ratio ten times greater than lithium-ion batteries. Consequently, it offers much greater range while being lighter and occupying smaller volumes. It can also be recharged in a few minutes, similarly to gasoline vehicles.
A light bulb lights up with a potential difference of 120 V and a current of 1.5 A. What is the energy consumption of the light bulb?
Power consumption = (voltage) x (current)
Power = (120 V) x (1.5 A)
Power = 180 watts
But 1 watt = 1 Joule/second
180 watts = 180 Joule/second
Energy consumption of the light bulb =
(180) x (number of seconds it's turned on) Joules
Light travels 300 000 000 m/s and one year has approximately 32 000 000 second a light year is the distance light travels in one year
Explanation:
It is given that,
Speed of light, [tex]v=300 000 000\ m/s=3\times 10^8\ m/s[/tex]
Seconds in 1 year, [tex]t=32 000 000=32\times 10^6\ s[/tex]
We need to find the distance traveled by light in one year. Speed of an object is given by :
[tex]v=\dfrac{d}{t}[/tex]
So,
[tex]d=v\times t\\\\d=3\times 10^8\times 32\times 10^6\\\\d=9.6\times 10^{15}\ m[/tex]
Since,
[tex]1\ \text{light year}=9.46\times 10^{15}\ m\\\\1\ m=\dfrac{1}{9.46\times 10^{15}}\ \text{ly}\\\\9.6\times 10^{15}\ m=\dfrac{9.6\times 10^{15}}{9.46\times 10^{15}}\\\\d=1.01\ \text{ly}[/tex]
So, the distance covered by light is 1.01 light years.
a skydiver jumped out of a plane and fell 9 miles to the ground. his average speed while falling was 174 miles/hour. how much time did the dive last?
Answer:
t = 0.051 seconds
Explanation:
Given that,
A skydiver jumped out of a plane and fell 9 miles to the ground. It means 9 miles is the distance covered.
The average speed of the skydiver is 174 miles/hour
We need to find the time for which he dive last. It means t is the time taken. Total distance covered divided by time taken is called average speed. So,
[tex]v=\dfrac{d}{t}\\\\t=\dfrac{d}{v}\\\\t=\dfrac{9}{174}\\\\t=0.051\ s[/tex]
So, a skydiver dive for 0.051 seconds.
Which of the following does each different kind of atom represent?
O A. A nucleus
O B. An element
O C. An electron
OD. A neutron
Answer:
B
Explanation:
because atoms make up an element.
Answer:
B
Explanation:
it's b because an element makes up an atom and signifies the number of element in atom e.g (H2) the two signifies the number of atoms
sliding friction is _ than the static friction.
Answer:
less
Explanation:
Sliding friction is always less than static friction. This is because in sliding friction, the bodies slide with each other and thus the effect of friction is not more. However, it does not happen in the case of static friction.
A diver releases an air bubble of volume 3.0 cm3 from a depth of 18 m below the surface of a lake, where the temperature is 9.0 ∘C. Part A What is the volume of the bubble when it reaches just below the surface of the lake, where the temperature is 22 ∘C?
Answer:
Explanation:
We shall apply gas law formula to get the solution .
P₁ V₁ / T₁ = P₂ V₂ / T₂
P₁ = 10⁵ + 18 x 10³ x 9.8 where 10⁵ Pa is atmospheric pressure at surface
= 1.764 x 10⁵ + 10⁵
= 2.764 x 10⁵
2.764 x 10⁵ x 3 / ( 273 + 9 ) = 10⁵ x V₂ / ( 273 + 22 )
V₂ = 8.67 cm³
Which force acts on a body if it is fully or partially immersed in a
liquid?
Answer:
Buoyant Force
Explanation:
That's literally the definition of the buoyant force
Why does fire has not any shadow?