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MArishka [77]
2 years ago
15

Need help ASAP, 1 MC

Physics
1 answer:
stepladder [879]2 years ago
3 0

Answer:

The first one is the only one that is true all the time

Explanation:

The second one may be true if friction is high enough.

The other three are false all the time

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Compute the moon's centripetal acceleration in its orbit around the earth. Recall that the moon orbits the earth very 38 days an
wlad13 [49]
Centripetal acceleration, Ac = V^2 / R.

V = tangential speed
R = radius of the orbit

V = 2πR / T

R = 240,000 miles
T = 28 days [ i am correcting what I think is an error, because the moon orbits the earth every 28 days]

V = 2π(240,000miles)*(1,609m/miles)/(28days*24h/day*3600s/h)

V = 1,002.9m/s

Ac = V^2 / R = 0.0026 m/s^2 

The force that cauces this acceleration is the gravity of our planet, as stated Lord Isaac Newton.

 
6 0
4 years ago
If a wave has a wavelength of 10 m and a speed of 2.5×108 m/s (this is 250000000 m/s) what is the frequency of the wave?
lakkis [162]

Answer:

The wavelength result is 3 m. Most common velocities: Light in vacuum (air) = 300,000 km/s. Light in water = 225,000 km/s. Sound in air = 340 m/s. Sound

Explanation:

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3 years ago
The height of the Washington Monument is measured to be 170 m on a day when its temperature is 35.0°C. What will the change in i
Alecsey [184]

Answer:

The deformation is 0.088289 m

The final height of the monument is 170-0.088289 = 169.911702 m

Explanation:

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So, let us take the average value

(5.5+14.1)/2 = 9.8×10⁻⁶ /K

Change in temperature = 35-(-18) = 53 K = ΔT

Original length = 170 m = L

Linear thermal expansion

\frac{\Delta L}{L} = \alpha\Delta T\\\Rightarrow \Delta L=\frac{\alpha\Delta T}{L}\\\Rightarrow \Delta L=9.8\times 10^{-6}\times 53\times 170

The deformation is 0.088289 m

The final height of the monument is 170-0.088289 = 169.911702 m (subtraction because of cooling)

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3 years ago
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Shkiper50 [21]

Energy cannot be created or destroyed. This statement is known as law of conservation of energy, and it implies that whenever a certain form of energy does change, the loss of this form of energy must have converted into an another type of energy. A typical example is an object falling to the ground: initially, the object has gravitational potential energy. As the object falls down, it loses potential energy (since its altitude from the ground decreases), but it acquires kinetic energy (because its velocity increases). In this example, potential energy has converted into kinetic energy, but the total energy of the object has remained constant.

5 0
3 years ago
In nuclear reaction 5 kg of reactants give 2kg of products
dlinn [17]
Choice A is correct.======Kinetic energy equation:   KE = (1/2)(m)(v²)This tells us that KE is directly proportional to mass and the square of velocity. In other words, the more mass and more velocity an object has, the more kinetic energy.If an object is sitting at the top of a ramp, there is no velocity and therefore no kinetic energy.    Choices B and D are wrong.A golf ball has more mass than a ping-pong ball, so a ping-pong ball would have less kinetic energy than a golf ball rolling off the end of a ramp.    Choice C is wrong.Choice A is correct.


6 0
3 years ago
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