Answer:
C. How bright it seems to us
Explanation:
The ratio of the distance moved by the point at which the effort is applied in a simple machine to the distance moved by the point at which the load is applied, in the same time. In the case of an ideal (frictionless and weightless) machine, velocity ratio = mechanical advantage. Velocity ratio is sometimes called distance ratio.
Answer:B)439.21 Hz
Explanation:
Given
velocity of train 
frequency of train 
speed of sound 
frequency from Doppler effect can be calculated by





Answer:
A
Explanation: I agree with A
Answer:
let current flow be x
Explanation:
than we know potential difference = energy supply / charge then 120 = 10 /x then x=12 therefore pd = 12 v