A body of mass 2 kg is thrown up vertically with K.E. of 490 joules. I

1.	A body of mass 2 kg is thrown up vertically with K.E. of 490 joules. If the acceleration due to gravity is 9.8 m/s2, the height at which the K.E of the body becomes half of its original value is given by :(A) 50m (B) 12. 5m(C) 25m (D) 10m.
Answer» Answer is (B) 12. 5m When he kinetic energy is halved, the potential energy s equal to the kinetic energy. That is mgh = (490/2)J = 245 J. this gives h =12.5 m.

A body of mass 2 kg is thrown up vertically with K.E. of 490 joules. If the acceleration due to gravity is 9.8 m/s2, the height at which the K.E of the body becomes half of its original value is given by :(A) 50m (B) 12. 5m(C) 25m (D) 10m.

Answer»

Answer is (B) 12. 5m

When he kinetic energy is halved, the potential energy s equal to the kinetic energy. That is mgh = (490/2)J = 245 J. this gives h =12.5 m.

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A body of mass 2 kg is thrown up vertically with K.E. of 490 joules. If the acceleration due to gravity is 9.8 m/s2, the height at which the K.E of the body becomes half of its original value is given by :(A) 50m (B) 12. 5m(C) 25m (D) 10m.

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