A 2 kg object accelerates from 3 m/s to 7 m/s. What is the change in kinetic energy?
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ΔK=½m(v²-u²).
With m=2, ΔK=49-9 = 40 J.
Practice NAT Physics questions with answers and explanations.
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ΔK=½m(v²-u²).
With m=2, ΔK=49-9 = 40 J.
Choose an option to check your answer.
Momentum is p=mv.
P=6×4 = 24 kg·m/s.
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Impulse equals change in momentum.
J=3(8-2)=18 N·s.
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Impulse is FΔt for constant force.
50×0.2 = 10 N·s.
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A body in rotational equilibrium has no angular acceleration.
Clockwise and counterclockwise torques balance.
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Work is W=Fd when force and displacement are parallel.
W=20×5 = 100 J.
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Use W=Fd cosθ.
W=10×4×cos60° = 20 J.
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Kinetic energy is ½mv².
K=½×4×9 = 18 J.
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K=½mv².
K=½×2×100 = 100 J.
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Potential energy change is mgh.
5×10×8 = 400 J.
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Power is work divided by time.
P=600/3 = 200 W.
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Energy transferred is Pt.
1000×20 = 20,000 J.