Physics
Work and Energy
Page 12 of 23
#89 Energy stored in a spring stretched by $x$ is:
A) $kx$
B) $kx^2$
C) $k/x$
D) $\tfrac12 kx^2$
#90 For a conservative force, the potential energy function $U$ satisfies:
A) $\nabla\cdot\vec F=U$
B) $\vec F=+\nabla U$
C) $\vec F=-\nabla U$
D) $\nabla\times\vec F=\nabla U$
#91 Energy stored in a spring stretched by $x$ is:
A) $k/x$
B) $\tfrac12 kx^2$
C) $kx$
D) $kx^2$
#92 A constant force $F=50\,\text{N}$ acts through $s=4\,\text{m}$ at $\theta=90^\circ$. The work done is:
A) $F/s$
B) $0$
C) $Fs$
D) $F+s$
#93 Instantaneous power delivered by a constant force is:
A) $P=F^2v$
B) $P=Fv\sin\theta$
C) $P=F/v$
D) $P=\vec F\cdot\vec v$
#94 Dimensions of power are:
A) $M^{0}L^{0}T^{-1}$
B) $ML^{2}T^{-3}$
C) $ML^{2}T^{-2}$
D) $MLT^{-2}$
#95 For a conservative force, the potential energy function $U$ satisfies:
A) $\nabla\cdot\vec F=U$
B) $\vec F=+\nabla U$
C) $\nabla\times\vec F=\nabla U$
D) $\vec F=-\nabla U$
Page 12 of 23
Register or Login for comments
Comments: