A horse accelerates from rest for 1 s and covers a distance D. If instead the accelerates from rest with the same accelerations for 2 s will the distance it covers be equal to 2D, 4D, or 9D

4D

Explanation:

We will use 2nd equation of motion in this question:

s = Vi t + (0.5)gt²

where,

s = distance covered

t = time taken

g = acceleration due to gravity

For t = 1 s:

s = D

Therefore,

D = (0 m/s)(1 s) + (0.5)g(1 s)²

D = 0.5g   equation (1)

For t = 2 s:

s = D

Therefore,

s = (0 m/s)(1 s) + (0.5)g(2 s)²

s = 0.5g(4)

using equation (1):

s = 4D

therefore, correct answer is:

4D

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.