Question

A stone of mass 50g is thrown vertically upwards with a velocity of 15m/s. Calculate :
(a) The potential energy at the greatest height
(b) The kinetic energy on reaching the ground
(c) The total energy at its half way point​

Answer 1

Answer:

$a) \: \: \: \: \frac{15}{8} \: \: joules \\ \\ \\ b) \: \: \frac{15}{8} \: \: \: joules \\ \\ c) \: \: \: \frac{15}{8} \: \: \: joules$

Explanation:

${u}^{2} = 2gh \\ h = \frac{ {u}^{2} }{2g} = \frac{ {15}^{2} }{2 \times 10} = \frac{1 5\times 15}{20} = \frac{15}{4} \: m \\ \\ a) \: \: \: potential \: energy \: = \: mgh \\ = \frac{50}{1000} \times 10 \times \frac{15}{4} \\ \\ = \frac{1}{2} \times \frac{15}{4} \\ \\ = \frac{15}{8} \: joules. \\ \\ \\ \\c) \: \: \: \: \: \: \: \: kinetic \: \: energy \: on \: reaching \: the \: ground \: = \: \\ potential \: energy \: at \: the \: highest \: point \: \\ = \frac{15}{8} \: \: joules \: . \\ \\ c) \: \: \: \: \: \: \: total \: energy \: at \: its \: halfway \: point \: \\ = kinetic \: energy \: on \: reaching \: the \: ground \: \\ = \frac{15}{8} \: \: joules \: \: .$