Advertisements
Advertisements
प्रश्न
How fast should a man of 50 kg run so that his kinetic energy be 625 J?
Advertisements
उत्तर
We have to find the speed of the running man. We have,
Mass of the man (m) = 50 kg
Kinetic energy of the man (K.E) = 325 J
So, we use the expression of kinetic energy to find the unknown quantity as,
`K.E = 1/2 mv^2`
Where,
KE - Kinetic Energy
m - Mass
v - Speed
So,
`v = sqrt((2(K.E))/((m))`
Therefore ,
`v = sqrt((2(625))/((50))` m/s
= `sqrt(25)` m/s
= 5 m/s
So , the man should be running with a speed of 5 m/s .
APPEARS IN
संबंधित प्रश्न
Two toy-cars A and Bof masses 200 g and 500 g respectively are moving with the same speed. Which of the two has greater kinetic energy?
Two bodies of equal masses are moving with uniform velocities v and 2v. Find the ratio of their kinetic energies.
A body of mass 10 kg is moving with a velocity 20 m s-1. If the mass of the body is doubled and its velocity is halved, find:
- the initial kinetic energy, and
- the final kinetic energy.
The momentum of a bullet of mass 20 g fired from a gun is 10 kg.m/s. The kinetic energy of this bullet in kJ will be :
Which of the following does not posses the ability to do work not because of motion?
If an object has 0 momentum, does it have kinetic energy? Explain your answer.
What are the uses of mechanical energy?
Explain the types of mechanical energy.
When stored water falls down, potential energy of water is converted into ______.
When a bell fixed on a cycle rings, then the energy conversion that takes place is ______.
