Answer
$93.8\ J$
Work Step by Step
Mass of the snow ball $m=1.50\ kg$
Initial velocity of snow ball $v_i=20\ m/s$
Angle $\theta=34^{\circ}$
Initial kinetic energy $KE_i = \frac{1}{2}mv_i^2$
Substituting and solving:
$KE_i = \frac{1}{2}(1.5\ kg) (20\ m/s)^2$
$KE_i =300\ J$
Final kinetic energy $KE_f=\frac{1}{2}mv_f^2$
Substituting and solving:
$KE_f=\frac{1}{2}(1.50\ kg)(20\ m/s\ cos34^{\circ})^2$
$KE_F = 206.19\ J$
Change in gravitation potential energy is equal to change in kinetic energy since ball is going up which works against gravity.
$\Delta PE =KE_i - KE_f$
$\Delta PE =300\ J- 206.19\ J$
$\Delta PE =93.8\ J$
