Questions from College Physics

Q: Under favorable conditions, the human eye can detect light waves with

Under favorable conditions, the human eye can detect light waves with intensities as low as 2.5 × 10−12 W/m2. (a) At this intensity, what is the average power incident on a pupil of diameter 9.0 mm?...

Q: In Fig. 17.13, why is the person touching

In Fig. 17.13, why is the person touching the dome of the van de Graaff generator not electrocuted even though there may be a potential difference of hundreds of thousands of volts between him and the...

Q: The electric field just above Earth's surface on a clear day in

The electric field just above Earth's surface on a clear day in an open field is about 150 V/m downward. Which is at a higher potential: Earth or the upper atmosphere?

Q: Humans can hear sounds with frequencies up to about 20.0

Humans can hear sounds with frequencies up to about 20.0 kHz, but dogs can hear frequencies up to about 40.0 kHz. Dog whistles are made to emit sounds that dogs can hear but humans cannot. If the part...

Q: A stone is launched straight up by a slingshot. Its initial

A stone is launched straight up by a slingshot. Its initial speed is 19.6 m/s, and the stone is 1.50 m above the ground when launched. (a) How high above the ground does the stone rise? (b) How much...

Q: A beam of electrons traveling with a speed of 3.0

A beam of electrons traveling with a speed of 3.0 × 107 m/s enters a uniform, downward electric field of magnitude 2.0 × 104 N/C between the deflection plates of an oscillosc...

Q: You are asked to hang a uniform beam and sign using a

You are asked to hang a uniform beam and sign using a cable that has a breaking strength of 417 N. The store owner desires that it hang out over the sidewalk as shown. The sign has a weight of 200.0 N...

Q: Two long, straight wires, each with a current of 12

Two long, straight wires, each with a current of 12.0 A, are placed on two corners of an equilateral triangle with sides of length 2.50 cm as shown. Both of the wires have a current into the page. (a...

Q: A neutron, with rest energy 939.6 MeV, has

A neutron, with rest energy 939.6 MeV, has momentum 935 MeV/c downward. What is its total energy?

Q: 1. A leopard starts from rest at t = 0 and

1. A leopard starts from rest at t = 0 and runs in a straight line with a constant acceleration until t = 3.0 s. The distance covered by the leopard between t = 1.0 s and t = 2.0 s is (a) the same as...