Question

How does kinetic energy change with speed?

Answer 1

When an object is in motion it gains kinetic energy. When we apply force to an object work is done and the energy gets transferred to the object making it move at a constant velocity. The energy that is transferred is referred to as kinetic energy. This kinetic energy is always dependent on the mass and the speed of the object. We can see how the kinetic energy changes with the speed using the formula of kinetic energy.

Complete step by step solution:
Speed can be given by distance divided by time. Velocity is the vector form of the speed. That is velocity gives both the magnitude of the speed and the direction of the speed. So let us consider speed and velocity as the same quantity. We know the formula for kinetic energy. The formula is given as,
$K.E = \dfrac{1}{2}m{v^2}$
Here $m$is the mass of the object
$v$is the velocity of the object
We can see from the formula that the kinetic energy is directly proportional to the square of the velocity. Therefore we can say that if there is an increase in the speed then the kinetic energy also increases. If there is a decrease in the speed then the kinetic energy also decreases. If the speed increases by the factor of two then the kinetic energy increases by the factor of four than the initial kinetic energy. If the speed increases by the factor of three then we can say that the kinetic energy increases by the factor of nine than the initial kinetic energy.
Note: This change is obvious because the faster an object is moving, the greater the force it can exert and therefore the greater the energy of the object be. We can see numerous examples of kinetic energy in nature. For example, a bird flying in the air, a whale moving through the water, a speeding car, a flying Frisbee, etc.