Questions from College Physics

Q: A gold wire of 0.50 mm diameter has 5.

A gold wire of 0.50 mm diameter has 5.90 × 1028 conduction electrons per cubic meter. If the drift speed is 6.5 µm/s, what is the current in the wire?

Q: A uniform magnetic field of 0.50 T is directed to

A uniform magnetic field of 0.50 T is directed to the north. At some instant, a particle with charge +0.020 μC is moving with velocity 2.0 m/s in a direction 30° north of east. (a) What is the magnit...

Q: When we talk about the potential difference between the plates of a

When we talk about the potential difference between the plates of a capacitor, shouldn't we really specify two points, one on each plate, and talk about the potential difference between those points?...

Q: An above-ground swimming pool is filled with water (total

An above-ground swimming pool is filled with water (total mass M) to a height h. Explain why the gravitational potential energy of the water (taking U = 0 at ground level) is /. Where does the factor...

Q: 1. Which of these statements are postulates of Einstein's special relativity

1. Which of these statements are postulates of Einstein's special relativity? (1) The speed of light is the same in all inertial reference frames. (2) Moving clocks run slow. (3) Moving objects are co...

Q: In Fig. 20.2, the distance between the rails

In Fig. 20.2, the distance between the rails is L = 5.0 cm. The metal rod is sliding to the right at v = 16 cm/s and the magnetic field has magnitude B = 0.75 T. The rod and rails have negligible resi...

Q: A light wave passes through a hazy region in the sky.

A light wave passes through a hazy region in the sky. If the electric field vector of the emerging wave is one quarter that of the incident wave, what is the ratio of the transmitted intensity to the...

Q: A sphere of copper is subjected to 100 MPa of pressure.

A sphere of copper is subjected to 100 MPa of pressure. The copper has a bulk modulus of 130 GPa. By what fraction does the volume of the sphere change? By what fraction does the radius of the sphere...

Q: You will be hiking to a lake with some of your friends

You will be hiking to a lake with some of your friends by following the trails indicated on a map at the trail-head. The map says that you will travel 1.6 mi directly north, then 2.2 mi in a direction...

Q: You are hiking through a lush forest with some of your friends

You are hiking through a lush forest with some of your friends when you come to a large river that seems impossible to cross. However, one of your friends notices an old metal barrel sitting on the sh...