Answer:
(a) 0.343 m/s
(b) 0.012 m/s
Explanation:
(a) From the question above,
MV = mv............................... Equation 1
Where M = mass of the rifle, V = recoiling speed of the rifle, m = mass of the bullet, v = velocity of the bullet.
make V the subject of the equation
V = mv/M........................... Equation 2
Given: m = 3.5 g = 0.0035 kg, v = 250 m/s, M = 25 N = 25/9.8 = 2.55 kg.
Substitute into equation 2
V = (0.0035×250)/2.55
V = 0.343 m/s.
(b) Similarly,
(M'+M)V' = mv....................... Equation 3
Where M' = mass of the marksman, V' = recoiling speed of the shooter and rifle
make V' the subject of the equation
V' = mv/(M'+M)................... Equation 4
Given: m = 3.5 g = 0.0035 kg, v = 250 m/s, M = 25 N = 25/9.8 = 2.55 kg, M' = 650 N = 650/9.8 = 66.33 N
Substitute into equation 4
V' = (0.0035×250)/(66.33+2.55)
V' = 0.8125/68.88
V' = 0.012 m/s
