Answer:
t=0.5 seconds
Step-by-step explanation:
Given that,
Force, F = 200 N
Mass of a cart, m = 20 kg
Initial speed of a cart, u = 3 m/s
Final speed, v = 8 m/s
Let t is the time for which the force is applied. Force applied to an object is given by :
F = ma
or
![F=(m(v-u))/(t)\\\\t=(m(v-u))/(F)\\\\t=(20* (8-3))/(200)\\\\t=0.5\ s](https://img.qammunity.org/2021/formulas/physics/college/63dp0k4jcx8a736y7i71wx30e0roaow205.png)
So, for 0.5 seconds the force is applied.