Question

A projectile with a mass of 0.270 kg is fired at and embeds itself in a stationary target with a mass of 2.79 kg. The target and embedded projectile fly off after being struck. Determine the percent of the projectile's incident kinetic energy carried off by the target-projectile combination.

Answer 1

here,

the mass of projectile , m1 = 0.27 kg

mass of stationary target , m2 = 2.79 kg

let the initial velocity be u and final velocity be v

using conservation of momentum

m1 * u = (m1 + m2) * v

0.27 * u = (0.27 + 2.79) * v

solving for v

v = 0.0882 * u

the percent of the projectile's incident kinetic energy carried off by the target-projectile combination , % = (0.5 * (m1 + m2) * v^2) /(0.5 *m1 * u^2) * 100

% = ((2.79 + 0.27) ( (0.0882 u)^2) /(0.27 * u^2)) * 100

% = 8.82 %