Home
Class 12
PHYSICS
A ball of mass2 kg and another of mass 4...

A ball of mass`2 kg` and another of mass `4 kg` are dropped together from a `60` feet tall building . After a fall of `30` feet each towards earth , their respective kinetic energies will be the ratio of

A

`sqrt2:1`

B

`1:4`

C

`1:2`

D

`1:sqrt2`.

Text Solution

Verified by Experts

The correct Answer is:
C
Ratio of their kinetic energy is given as
`(KE_1)/(KE_2) = ((1//2)m_1 v_(1)^(2))/((1//2)m_2 v_(2)^(2))`
Again, `v^(2) = 2gs` (zero initial velocity) which is same for both ball.
`therefore (KE_1 )/(KE_2)= (m_1)/(m_2) = (2)/(4)= (1)/(2)`.
Promotional Banner

Topper's Solved these Questions

  • WORK, POWER, ENERGY

    MTG-WBJEE|Exercise EXERCISE (WB JEE WORKOUT) CATEGORY 2 : Single Option Correct Type (2 Mark)|15 Videos

  • WORK, POWER, ENERGY

    MTG-WBJEE|Exercise EXERCISE (WB JEE WORKOUT) CATEGORY 3 : One or More than One Option Correct Type (2 Marks)|10 Videos

  • WAVE OPTICS

    MTG-WBJEE|Exercise WB JEE PREVIOUS YEARS QUESTION (MCQ.s)|9 Videos

Similar Questions

Explore conceptually related problems

A ball of mass 12 kg and another of mass 6 kg are dropped from a 60 feet tall building after a fall of 30 feet each towards earth, their kinetic energies will be in the ratio of .

Two bodies of masses 4 kg and 5 kg are moving with equal momentum. Then the ratio of their respective kinetic energies is

A block of mass 5 kg is dropped from top of a building. Then the mamiitude of force applied by the block on the earth whne falling is :

Two balls of equal size are dropped from the same height from the roof of a building . One ball has twice the mass of the other. When the balls the ground, how do the kinetic energies of the two balls compare ?

Two bodies A (of mass 1 kg ) and B (of mass 3 kg ) are dropped from heights of 16 m and 25 m . Respectively. The ratio of the time taken to reach the ground is :

Two spheres of same size , one of mass 2 kg and another of mass 4kg are dropped smalltanausly from the top of is 72 as light tower When they are 1m above the ground the two sphers have the same

Two bodies A (of mass 1 kg ) and B (of mass 3kg ) are dropped from heights of 16m and 25m ,respectively What is the ratio of the times taken by them to reach the ground?