Question

A 2kg object is released from rest froma height of 3m above earths surface. how much kinetic energy does the object havve when it reaches a height of 1ma. 2.5 Jb. 10 Jc. 20 Jd. 30 Je. 40 J

Answer 1

Answer:

Kinetic energy, E = 40 Joules

Explanation:

Given that,

Mass of the object, m = 2 kg

It is released from rest from a height of 3 m above Earth's surface, $h=3\ m$

We need to find the kinetic energy the object have when it reaches a height of 1 m, $h'=1\ m$. We know that the total energy is conserved. So, the kinetic energy at some height is equal to its kinetic energy.

$E=mg(h-h')$

$E=2\times 10\times (3-1)$

E = 40 Joules

So, the kinetic energy of the object when it reaches a height of 1 m is 40 joules. Hence, this is the required solution.