Question

A constant force acting on a body of mass 10kg changes its’velocity from70m/s to120 m/s while the body covers a distance of 200 m. Find the acceleration produced by the applied force and find the applied force.

Answer 1

a) Let's first find the acceleration of the body from the kinematic equation:

$$v^2 = v_0^2 + 2as,$$ $$a = \dfrac{v^2 - v_0^2}{2s} = \dfrac{(120 \dfrac{m}{s})^2 - (70 \dfrac{m}{s})^2}{2 \cdot 200 m} = 23.75 \dfrac{m}{s^2}.$$

b) Finally, from the Newton's Second Law of Motion, we can find the applied force:

$$F = ma = 10 kg \cdot 23.75 \dfrac{m}{s^2} = 237.5 N.$$

Answer:

a) $a = 23.75 \dfrac{m}{s^2}.$

b) $F = 237.5 N.$