Question

The body of mass 2kg undergoes a constant horizontal acceleration of 5m/s². Calculate the resultant horizontal force acting on the body. What will be the resultant force when it moves with a uniform velocity of 10m/s²

Answer 1

According to the Newton's second law, the resultant foce acting on a body is equal to:

$$F = ma$$

where $m = 2kg$ is the mass of the body and $a = 5m/s^2$ is its acceleration. Thus:

$$F = 2\cdot 5 \space (kg\cdot m)/s^2 = 10N$$

When abody moves with a uniform velocity, it does not have any acceleration ($a = 0$ ). Thus, by the Newton's second law, the resultant force also is zero.

Answer. 1) 10N. 2) 0N.