Question

Proyektil dengan massa 10 gram ditembak dari senapan dengan massa 5 kg. Kecepatan proyektil sesaat setelah memotret dari laras adalah 200 m / s. Hitung kecepatan gerakan menyentak senapan pada saat tembakan proyektil dari senapan.

Answer 1

Answer:

-0.4 m/s

Explanation:

According to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.

The total momentum before the shot is zero, since they are both at  rest:

$p_i = 0$

While the total momentum after the shot can be written as:

$p_f = mv+MV$

where

m = 10 g = 0.010 kg is the mass of the bullet

M = 5 kg is the mass of the rifle

v = 200 m/s is the velocity of the bullet

V is the recoil velocity of the rifle

Since the total momentum is conserved, we can write:

$p_i = p_f$

So

$0=mv+MV$

And solving for V, we find the recoil velocity:

$V=-\frac{mv}{M}=-\frac{(0.010)(200)}{5}=-0.4 m/s$

and the negative sign indicates that the velocity is opposite to the bullet.