Question

What horizontally-applied force will accelerate a 400-kg crate at 1 m/s^2 across a factory room floor against a friction force of half its weight?

A) 600 N B) 1600 N C) 2000 N D) 2400 N E) None of the above

Answer 1

Answer:

option D

Explanation:

given,

mass of the crate = 400 Kg

acceleration of the crate = 1 m/s²

frictional force =  half its weight

weight of the crate,= mg

                                = 400 x 10 = 4000 N

frictional force,f = 0.5 x 4000 = 2000 N

using newtons second law

F - f = m a

F = m a + f

F = 400 x 1 + 2000

F = 2400 N

Horizontal force applied is equal to 2400 N

The correct answer is option D