Problem 5: A proton is moving with a speed of 1 × 107 m/s, passes through a 0.020 cm thick sheet of paper and emerges with a speed of 2.0 × 106 ms-1. Assuming uniform deceleration, find retardation and time taken to pass through the paper.
Given: vi = 1 × 107 ms-1, Thickness = distance = s = 0.02 cm = 0.02 × 10-2 m,
vf = 2.0 × 106 ms-1
Find: Deceleration a and time t
To find the required quantities, we use equation of motion,
Put the values
This equation gives the deceleration of proton.
To find the time taken to pass through the paper, we use equation of motion vf = vi + at. Put values,