Answer to Question #240860 in Molecular Physics | Thermodynamics for Kelani

Question

A projectile of mass m is fired horizontally with an initial speed of v₀ from a height of h above a flat, desert surface. Neglecting air friction, at the instant before the projectile hits the ground, find the following in terms of m, v₀, h, and g.

(a) the work done by the force of gravity on the projectile

W = 

(b) the change in kinetic energy of the projectile since it was fired

ΔKE = 

(c) the final kinetic energy of the projectile

KE_f = 

Answer 1

a)

$W=mgh,$

b)

$\Delta KE=mgh-0=mgh,$

c)

$KE_f=mgh+\frac{mv_0^2}2.$