In: Physics
An average force of 10 N is exerted on a wagon through a 5.0 m distance. The wagon has a mass of 2.0 kg.
a) What kinetic energy will the wagon gain?
b) What will be the final speed of the wagon?
Force exerted on wagon , F = 10 N
Distance = 5.0 m
mass of wagon = 2.0 kg
a)
By Work-Energy theorem --
work done on the body by a Force ,F acting on it is equal to the change in kinetic energy
Gain in kinetic Energy
Gain in Kinetic Energy = Work done
= W
But W = Force x distance ( travelled by wagon )
= 10 N * 5 m
= 50 N.m
= 50 j
gain in kinetic energy by wagon = 50 j
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b)
We know that , KE = W
= 7.07m/s
Final speed of the wagon = 7.07m/s
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The work donw by a force on a body equals change in KE
IT IS SHOWN BY NEWTON'S SECOND LAW.
F = ma
mass = mass of the body
a = acceleration
But, acceleration a =
s=distance reavelled by the body
Velocity increases from Vi to Vf
F= ma
multiply both sides by 's'
F= ma
we know W = FS
Therefore ,
mass is constant and velocity increases form Vf to Vi
THUS SHOWN