wooden floor at a constant speed of 1.0 m/s. The coefficient of kinetic friction is 0.15. Now you double the force on the box. How long would it take for the velocity of the crate to double to 2.0 m/s?

Time = 1.36s

Explanation:

coefficient of kinetic friction = μk

μk = F/N = F / mg

where m = mass of the body

g = acceleration due to gravity.

Doubling the force on the box we have,

μk = 2ma/mg

hence μk = 0.15/2 = 0.075

To determine the time it takes to reach a velocity of 2m/s from 1m/s.

From Newton law of motion,

v = u + a*t

for a deceleration of a = μk x g

2m/s = 1m/s + 0.075 x 9.8m/s² x t

t = (2m/s - 1m/s) / 0.735m/s²

t = 1.36 seconds ...

it will take the 1.36s for the crate to double to 2.0m/s