Question 22

A spherical body of mass 2 kg starting from rest acquires a kinetic energy of 10000 J at the end of 5$$^{th}$$ second. The force acted on the body is _____ N.

Correct Answer: 40

Given: $$m=2$$ kg, $$KE=10000$$ J at $$t=5$$ s, starts from rest.

$$\frac{1}{2}mv^2=10000 \Rightarrow v^2=10000 \Rightarrow v=100$$ m/s.

$$a = v/t = 100/5 = 20$$ m/s$$^2$$. $$F = ma = 2 \times 20 = 40$$ N.

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