Question

A 5kg block is pulled across a table by a horizontal force of 40 N with a frictional force of 8 N opposing the motion. Draw a force diagram and determine the net force. Then calculate the acceleration of the object.

Answer 1

Net force on the block is 32 N.

Acceleration of the object is 6.4 m/s².

Step-by-step explanation:

Let the acceleration of the object be
`a` m/s².

Given:

Mass of the block is,
`m=5\ kg`

Force of pull is,
`F=40\ N`

Frictional force on the block is,
`f=8\ N`

The free body diagram of the object is shown below.

From the figure, the net force in the forward direction is given as:

`F_(net)=F-f=40-8=32\ N`

Now, from Newton's second law of motion, net force is equal to the product of mass and acceleration. So,

`F_(net)=ma\\32=5a\\a=(32)/(5)=6.4\ m/s^2`

Therefore, the acceleration of the object in the forward direction is 6.4 m/s².