Question

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

Answer 1

Ff = 5.5 N

Step-by-step explanation:

Given:

M: 15kg

A: 16.3 m/s2

We use:

`f=ma`

force=mass*acceleration

`(15kg)(16.3m/s^(2) )=244.5N`

This means that 244.5 N is the net force on the object, and the right vector is showing 250 N, so to find the left vector - which would be a negative number (left direction) - we do

`(-Ff)+250N= 244.5N (net force)`

Which would give us 5.5 N in the left direction (Ff)

Hope This Helps!

Answer 2

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