Questions from College Physics

Q: A cylindrical steel bar is compressed by the application of forces of

A cylindrical steel bar is compressed by the application of forces of magnitude F at each end. What magnitude forces would be required to compress by the same amount (a) a steel bar of the same cross...

Q: Would a ground fault interrupter work if the circuit used dc current

Would a ground fault interrupter work if the circuit used dc current instead of ac? Explain.

Q: A ball of mass 0.10 kg moving with speed of

A ball of mass 0.10 kg moving with speed of 2.0 m/s hits a wall and bounces back with the same speed in the opposite direction. What is the change in the ball’s kinetic energy?

Q: Why must all reversible engines (operating between the same reservoirs)

Why must all reversible engines (operating between the same reservoirs) have the same efficiency? Try an argument by contradiction: imagine that two reversible engines exist with e1 > e2. Reverse one...

Q: By what percentage does the density of water increase at a depth

By what percentage does the density of water increase at a depth of 1.0 km below the surface?

Q: Find the magnetic field at point R, the midpoint of the

Find the magnetic field at point R, the midpoint of the left side of the square.

Q: In Section 22.3, we stated that an electric dipole

In Section 22.3, we stated that an electric dipole antenna should be aligned with the electric field of an EM wave for best reception. If a magnetic dipole antenna is used instead, should its axis be...

Q: A person in bare feet is standing under a tree during a

A person in bare feet is standing under a tree during a thunderstorm, seeking shelter from the rain. A lightning strike hits the tree. A burst of current lasting 40 µs passes through the ground; durin...

Q: When supplies of fossil fuels such as petroleum and coal dwindle,

When supplies of fossil fuels such as petroleum and coal dwindle, people might call the situation an “energy crisis.” From the standpoint of physics, why is that not an accurate name? Can you think of...

Q: A 4.0 N object is attached to the bottom of

A 4.0 N object is attached to the bottom of an ideal spring of spring constant 250 N/m. The spring is initially in its relaxed position. Write an equation to describe the motion of the object if it is...