An object has a mass of 15 kg and is accelerating to the right at 16.3 m/s2. The free-body diagram shows the horizontal forces acting on the object.

What is the frictional force, Ff, acting on the object?

5.5 N

15 N

244.5 N

494.5 N

Answer:

5.5 N

Refer to the free body diagram shown melow.

F = applied force

R = frictional force

m = 15 kg, the mass of the object

The acceleration (to the right) is 16.3 m/s², therefore

F - R = (15 kg) * (16.3 m/s²) = 244.5 N

The normal reaction is

N = mg = (15 kg) * (9.8 m/s²) = 147 N

The frictional force is

R = μN = 147μ N, where μ = coefficient of kinetic friction.

Let us check possible answers:

If R = 5.5 N, then μ = 5.5/147 = 0.0374 (very likely)

If R = 15 N, then μ = 15/147 = 0.102 (possible)

If R = 244.5 N, (Highly unlikely, exceed mg)

If R = 494.5 N, (highly unlikely, exceeds mg)

Answer:

The most reasonable answer is R = 5.5 N