1) The Rinetic energy of an objec of mass (m) moving with a velocity of smo u 25 J. What will be its kinetic energy when its velocity is doubled What will be its kinetic energy when its velocity is increased three time?
Answers
- The kinetic energy of an object of mass, m moving with a velocity of 5 ms-¹ is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?
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- Here, we are given that the kinetic energy of an object of mass ( m ) moving with a velocity of 5 ms-¹ is 25 J. We are asked to calculate it's kinetic energy if:
▪ Velocity is doubled.
▪ Velocity is increased three times.
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» We've to calculate the kinetic energy of the object for the given situation. We know, the kinetic energy is calculated by:
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where:
- m is the mass of the object.
- v is the velocity of object.
- Given kinetic energy and velocity are 25 J and 5 ms-¹.
⠀⠀━━━━━━━━━━━━━━━━━━━━━━━━━━━━━⠀⠀⠀
★ Case ( I ): Velocity is doubled.
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- Value of mass will remain same (2 kg) & the velocity will be 2 times the velocity in given question.
⠀⠀━━━━━━━━━━━━━━━━━━━━━━━━━━━━━⠀⠀⠀
★ Case ( II ): Velocity is increased three times.
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- Value of mass will remain same (2 kg) & the velocity will be 3 times the velocity given in the question.
Solution :
Here, we are given that the kinetic energy of an object of mass ( m ) moving with a velocity of 5 ms-¹ is 25 J. We are asked to calculate it's kinetic energy if :
» We've to calculate the kinetic energy of the object for the given situation. We know, the kinetic energy is calculated by:
where :
m is the mass of the object.
v is the velocity of object.
Given kinetic energy and velocity are 25 J and 5 ms-¹.
Substituting the values in formula :
m = 2
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★ Case ( I ) : Velocity is doubled.
Value of mass will remain same (2 kg) & the velocity will be 2 times the velocity in given question ,
Kinetic energy = 100 J .
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★ Case ( II ) : Velocity is increased three times.
Value of mass will remain same (2 kg) & the velocity will be 3 times the velocity given in the question,
Kinetic energy = 225 J .