Question

A body is projected vertically up. At certain height 'h' above the ground,. its PE and KE are in the ratio 1:4. Then at what height above the ground PE and KE will be in the-ratio 4:1

A. h4
B. 5 h
C. h/5
D. 4 h

Answer 1

The height above the ground where the potential energy (PE) and kinetic energy (KE) will be in the ratio 4:1 is directly proportional to v².

Step-by-step explanation:

To find the height above the ground where the potential energy (PE) and kinetic energy (KE) will be in the ratio 4:1, we can use the relationship between PE and KE.

According to the relationship 2gh=v², where g is the acceleration due to gravity and h is the height, we can set up the equation for the given ratio:

PE/KE = 1/4

Using the equation 2gh=v², we can substitute the ratio PE/KE with 1/4 and solve for h:

1/4 = 2gh/v²

Rearranging the equation to solve for h:

h = v²/(8g)

Therefore, the height h above the ground where PE and KE will be in the ratio 4:1 is directly proportional to v².

The correct answer is option D. 4h.