Questions from College Physics

Q: An object of 1.0 kg mass approaches a stationary object

An object of 1.0 kg mass approaches a stationary object of 5.0 kg at 10.0 m/s and, after colliding, rebounds in the reverse direction along the same line with a speed of 5.0 m/s. What is the speed of...

Q: Estimate the magnetic field at distances of 1 μm and 1 mm

Estimate the magnetic field at distances of 1 μm and 1 mm produced by a current of 3 μA along the medial nerve of the human arm. Model the nerve as a straight current-carrying wire. Compare with the m...

Q: The source and observer of a sound wave are both at rest

The source and observer of a sound wave are both at rest with respect to the ground. The wind blows in the direction from source to observer. Is the observed frequency Doppler-shifted? Explain.

Q: Imagine a long straight wire perpendicular to the page and carrying a

Imagine a long straight wire perpendicular to the page and carrying a current I into the page. Sketch some field lines with arrowheads to indicate directions.

Q: Kieran measures the magnetic field of an electron beam. The beam

Kieran measures the magnetic field of an electron beam. The beam strength is such that 1.40 × 1011 electrons pass a point every 1.30 μs. What magnetic field does Kieran measure at a distance of 2.00 c...

Q: If the molecule is initially at rest at θ = 90.

If the molecule is initially at rest at θ = 90.0°, what is its angular speed when it reaches θ = 0, assuming no other forces or torques? [Hint: First find the work done on each point charge.]

Q: Within cells, small organelles containing newly synthesized proteins are transported along

Within cells, small organelles containing newly synthesized proteins are transported along microtubules by tiny molecular motors called kinesins. What force does a kinesin molecule need to deliver in...

Q: A point charge q = +3.0 nC moves through

A point charge q = +3.0 nC moves through a potential difference ΔV = Vf − Vi = +25 V. What is the change in the electric potential energy?

Q: Unpolarized light is incident on a system of three ideal polarizers.

Unpolarized light is incident on a system of three ideal polarizers. The second polarizer is oriented at an angle of 30.0° with respect to the first, and the third is oriented at an angle of 45.0° wit...

Q: A standing wave has wavenumber 200 rad/m. What is

A standing wave has wavenumber 200 rad/m. What is the distance between two adjacent nodes?