Work and Energy
Dimensions of power are:
A) $M^{0}L^{0}T^{-1}$
B) $ML^{2}T^{-2}$
C) $MLT^{-2}$
D) $ML^{2}T^{-3}$
For a conservative force, the potential energy function $U$ satisfies:
A) $\nabla\times\vec F=\nabla U$
B) $\vec F=+\nabla U$
C) $\vec F=-\nabla U$
D) $\nabla\cdot\vec F=U$
At the bottom of a frictionless track, potential energy is minimum and kinetic energy is:
A) maximum
B) undefined
C) zero
D) minimum
Dimensions of power are:
A) $M^{0}L^{0}T^{-1}$
B) $ML^{2}T^{-3}$
C) $MLT^{-2}$
D) $ML^{2}T^{-2}$
At the bottom of a frictionless track, potential energy is minimum and kinetic energy is:
A) zero
B) maximum
C) undefined
D) minimum
Instantaneous power delivered by a constant force is:
A) $P=F/v$
B) $P=\vec F\cdot\vec v$
C) $P=Fv\sin\theta$
D) $P=F^2v$
A constant force $F=20\,\text{N}$ acts through $s=4\,\text{m}$ at $\theta=60^\circ$. The work done is:
A) $20s\,\cos60^\circ$
B) $F+s$
C) $F/s$
D) $Fs$
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