A bolt of mass 0.2 kg falls from the ceiling of an elevator moving down with an uniform speed of 5 ms-1. It hits the floor of the elevator (length of the elevator = 5 m) and does not rebound. The amount of heat produced by the impact is (Take g = 10 ms-2)

Question

A bolt of mass 0.2 kg falls from the ceiling of an elevator moving down with an uniform speed of 5 ms-1. It hits the floor of the elevator (length of the elevator = 5 m) and does not rebound. The amount of heat produced by the impact is (Take g = 10 ms-2) (A) 5 J (B) 10 J (C) 15 J (D) 20 J

Tardigrade Admin · Accepted Answer

Here, m = 0.2 kg, v = 5 ms-1 h = length of elevator = 5 m As relative velocity of the bolt w.r.t. elevator is zero, therefore, in the impact, only potential energy of the bolt is converted into heat energy. Amount of heat produced = Potential energy lost by the bolt = mgh = (0.2 kg) (10 ms-2) (5 m) = 10 J

Q. A bolt of mass $0.2 k g$ falls from the ceiling of an elevator moving down with an uniform speed of $5 m s^{- 1}$ . It hits the floor of the elevator (length of the elevator $= 5 m$ ) and does not rebound. The amount of heat produced by the impact is (Take $g = 10 m s^{- 2}$ )

$5 J$

$10 J$

$15 J$

$20 J$

Q. A bolt of mass 0.2kg falls from the ceiling of an elevator moving down with an uniform speed of 5ms−1. It hits the floor of the elevator (length of the elevator =5m) and does not rebound. The amount of heat produced by the impact is (Take g=10ms−2)

5J

10J

15J

20J

Here, m=0.2kg, v=5ms−1 h= length of elevator =5m As relative velocity of the bolt w.r.t. elevator is zero, therefore, in the impact, only potential energy of the bolt is converted into heat energy. Amount of heat produced = Potential energy lost by the bolt =mgh =(0.2kg)(10ms−2)(5m)=10J

Q. A bolt of mass $0.2 k g$ falls from the ceiling of an elevator moving down with an uniform speed of $5 m s^{- 1}$ . It hits the floor of the elevator (length of the elevator $= 5 m$ ) and does not rebound. The amount of heat produced by the impact is (Take $g = 10 m s^{- 2}$ )

$5 J$

$10 J$

$15 J$

$20 J$