Question

plz answer this fastly

Answer 1

Answer:

9)acceleration,a= 1/10 =0.1

Displacement,s =100 cm = 1m

Time,t= 4 sec

Using 2nd equation of motion,

s= ut + 1/2 at^2

1= u×4 + 1/2 × 0.1× 16

1= 4u + 0.8

0.2 = 4u

u = 0.2/4 = 0.05 m/s = 5cm/s

10)Let us say each bullet takes about 1/20 th of a second to come out of the          barrel of the gun.  Each bullet then accelerates from rest to a speed of 800 meters in a time duration of 1/20 = 0.05 sec.

Acceleration of a bullet = a = (800 - 0 ) / 0.05 sec = 16000 m /sec²

Force necessary to give the bullet this acceleration = m a

          = (150 /1000) kg * 16000 m/sec²

          = 2400 Newtons

The bullets exert the same amount of force on the machine gun as the machine gun exerted on the bullets.

Force necessary to hold the gun = recoil force of gun = 2400 Newtons

Hope this helps u and all the best!!