A spherical body of mass 2 kg starting from rest acquires a kinetic energy of 10000 J at the end of second. The force acted on the body is __________ N.
Show answer and solution
Answer: 40
Solution
Using work-energy theorem and kinematics: KE = (1/2)mv² = 10000 J, so v² = 10000, giving v = 100 m/s.
Since the body starts from rest and reaches 100 m/s in 5 seconds, acceleration a = 100/5 = 20 m/s².
Force = ma = 2 × 20 = 40 N.
Since the body starts from rest and reaches 100 m/s in 5 seconds, acceleration a = 100/5 = 20 m/s².
Force = ma = 2 × 20 = 40 N.
[JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)]