the kinetic energy of an object of mass 'm' moving with a velocity of 5cms^-1 is 25J. calculate its kinetic energy when its velocity is doubled..??
The kinetic energy is quadrupled if the velocity is doubled.
To calculate the kinetic energy of an object when its velocity is doubled, we need to understand the formula for kinetic energy. Kinetic energy is given by the equation:
K.E. = (1/2) * m * v^2
Where:
K.E. is the kinetic energy
m is the mass of the object
v is the velocity of the object.
In this case, we are given the mass 'm' and the initial velocity of 5 cm/s. We are also given that the initial kinetic energy is 25 J.
First, let's calculate the initial kinetic energy using the given values:
K.E. = (1/2) * m * v^2
25 = (1/2) * m * (5)^2
Now, let's solve the above equation to find the value of 'm':
25 = (1/2) * m * 25
25 = (1/2) * 25m
25 = 12.5m
m = 25/12.5
m = 2 kg
We have found the mass 'm' to be 2 kg.
Now, we need to calculate the kinetic energy when the velocity is doubled. Doubling the velocity means multiplying it by 2. So, the new velocity will be 2 * 5 = 10 cm/s.
Using the same formula for kinetic energy, and substituting the new values:
K.E. = (1/2) * m * v^2
K.E. = (1/2) * 2 * (10)^2
K.E. = (1/2) * 2 * 100
K.E. = 100 J
Therefore, the kinetic energy when the velocity is doubled is 100 J.