Work-energy applied to launching or projecting objects
Questions where a constant force acts over a short distance to launch or project an object (e.g., bowling machine, cricket ball), and the force magnitude or energy is to be found from the resulting motion.
A ball of mass 0.2 kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2 m while applying the force and the ball goes upto 2 m height further, find the magnitude of the force. Consider $g = 10$ m/s$^2$ (1) 22 N (2) 4 N (3) 16 N (4) 20 N
A cricket ball of mass 0.15 kg is thrown vertically up by a bowling machine so that it rises to a maximum height of 20 m after leaving the machine. If the part pushing the ball applies a constant force $F$ on the ball and moves horizontally a distance of 0.2 m while launching the ball, the value of $F$ (in N) is $\left( g = 10 \mathrm {~m} \mathrm {~s} ^ { - 2 } \right)$