The equation for the motion of the body under constant acceleration is:
v=u+atwhere:
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v is the velocity at time
t,
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u is the initial velocity (which is zero since the body is at rest),
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a is the constant acceleration,
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t is the time.
Therefore, the velocity at time
t is:
v=atThe power delivered to the body is the rate at which work is done, and it is given by:
P=Fvwhere:
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P is the power,
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F is the force acting on the body,
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v is the velocity of the body.
The force
F can be calculated using Newton’s second law:
F=mawhere:
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m is the mass of the body,
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a is the acceleration.
Thus, the power delivered to the body is:
P=ma⋅vSubstituting
v=at into the equation:
P=ma⋅(at)=ma2tThus, the power is directly proportional to time
t.
t Quick Tip: The power delivered to an object under constant acceleration is proportional to the time
t, because both velocity and force are linearly related to time in such motion.