A machine gun fires six bullets per second into a target. The mass of each bullet is 3 g and the speed 500 m / s. The power delivered to the bullets is

Question

A machine gun fires six bullets per second into a target. The mass of each bullet is 3 g and the speed 500 m / s. The power delivered to the bullets is (A) 1.5 kW (B) 2.25 kW (C) 0.75 kW (D) 375 W

Tardigrade Admin · Accepted Answer

The power delivered is the work done per second which again is equal to the total kinetic energy of the six bullets fired per second.
Hence power

P = 6

(kinetic energy of each bullet)

= 6 [\frac{1}{2} \times 3 \times 1 0^{- 3} \times (500)^{2}] J / s

= 2250 W = 2.25 kW

Q. A machine gun fires six bullets per second into a target. The mass of each bullet is $3 g$ and the speed $500 m / s$ . The power delivered to the bullets is

$1.5 kW$

$2.25 kW$

$0.75 kW$

$375 W$

The power delivered is the work done per second which again is equal to the total kinetic energy of the six bullets fired per second.
Hence power $P = 6$ (kinetic energy of each bullet)
$= 6 [\frac{1}{2} \times 3 \times 1 0^{- 3} \times (500)^{2}] J / s$
$= 2250 W = 2.25 kW$

Q. A machine gun fires six bullets per second into a target. The mass of each bullet is 3g and the speed 500m/s. The power delivered to the bullets is

1.5kW

2.25kW

0.75kW

375W