Questions from College Physics

Q: A very small charged block with a mass of 2.35

A very small charged block with a mass of 2.35 g is placed on an insulated, frictionless plane inclined at an angle of 17.0° with respect to the horizontal. The block does not slide down th...

Q: Within an insulated system, 418.6 kJ of heat is

Within an insulated system, 418.6 kJ of heat is conducted through a copper rod from a hot reservoir at +200.0°C to a cold reservoir at +100.0°C. (The reservoirs are so big that this heat exchange does...

Q: (a) Which has the larger buoyant force acting on it

(a) Which has the larger buoyant force acting on it when immersed in water, 1.0 kg of lead or 1.0 kg of aluminum? Explain. (b) Which has the larger buoyant force acting on it, 1.0 kg of steel that is...

Q: The Bohr model of the hydrogen atom proposed that the electron orbits

The Bohr model of the hydrogen atom proposed that the electron orbits around the proton in a circle of radius 5.3 × 10−11 m. The electric force is responsible for the radial acceleration of the electr...

Q: A student eats 2000 kcal per day. (a)

A student eats 2000 kcal per day. (a) Assuming that all of the food energy is released as heat, what is the rate of heat released (in watts)? (b) What is the rate of change of entropy of the surround...

Q: In gel electrophoresis, the mobility μ of a molecule in a

In gel electrophoresis, the mobility μ of a molecule in a particular gel matrix is defined as μ = v1/E, where v1 is the terminal speed of the molecule and E is the applied electric field strength. In...

Q: Humans cool off by perspiring; the evaporating sweat removes heat from

Humans cool off by perspiring; the evaporating sweat removes heat from the body. If the skin temperature is 35.0°C and the air temperature is 28.0°C, what is the entropy change of the universe due to...

Q: The graph shows the position x of a switch engine in a

The graph shows the position x of a switch engine in a rail yard as a function of time t. At which of the labeled times t0 to t7 is (a) ax 0, (d) vx = 0, (e) the speed decreasing?

Q: In an experiment to measure the Coulomb constant, a tiny sphere

In an experiment to measure the Coulomb constant, a tiny sphere with charge +7.0 nC is suspended from a spring. When two other tiny charged spheres, each with a charge of −4.0 µC, are placed in the po...

Q: A spherical rain drop of radius 1.0 mm has a

A spherical rain drop of radius 1.0 mm has a charge of +2.0 nC. The electric field in the vicinity is 2.0 kN/C downward. The terminal speed of an identical but uncharged drop is 6.5 m/s. The drag forc...