Questions from College Physics

Q: An x - ray tube used for cancer therapy operates at 4

An x - ray tube used for cancer therapy operates at 4.0 MV, with a beam current of 25 mA striking the metal target. Nearly all the power in the beam is transferred to a stream of water flowing through...

Q: A man wishes to vacuum his car with a canister vacuum cleaner

A man wishes to vacuum his car with a canister vacuum cleaner marked 535 W at 120. V. The car is parked far from the building, so he uses an extension cord 15.0 m long to plug the cleaner into a 120....

Q: A 2.0 x 102 - km - long high -

A 2.0 x 102 - km - long high - voltage transmission line 2.0 cm in diameter carries a steady current of 1.0 x 103 A. If the conductor is copper with a free charge density of 8.5 x 1028 electrons/m3, h...

Q: An aluminum wire having a cross - sectional area of 4.

An aluminum wire having a cross - sectional area of 4.00 x 10-6 m2 carries a current of 5.00 A. The density of aluminum is 2.70 g/cm3. Assume each aluminum atom supplies one conduction electron per at...

Q: An iron wire has a cross - sectional area of 5.

An iron wire has a cross - sectional area of 5.00 x 10-6 m2. Carry out steps (a) through (e) to compute the drift speed of the conduction electrons in the wire. (a) How many kilograms are there in 1 m...

Q: A battery having an emf of 9.00 V delivers 117

A battery having an emf of 9.00 V delivers 117 mA when connected to a 72.0 - Ω load. Determine the internal resistance of the battery.

Q: Consider the circuit shown in Figure P18.10. (

Consider the circuit shown in Figure P18.10. (a) Calculate the equivalent resistance of the 10.0 - Ω and 5.00 - Ω resistors connected in parallel. (b) Using the result of part...

Q: An unknown substance has a mass of 0.125 kg and

An unknown substance has a mass of 0.125 kg and an initial temperature of 95.0 °C. The substance is then dropped into a calorimeter made of aluminum containing 0.285 kg of water initially at 25.0 °C....

Q: Consider the circuit shown in Figure P18.11. Find

Consider the circuit shown in Figure P18.11. Find (a) The potential difference between points a and b and (b) The current in the 20.0 - Ω resistor. Figure P18.11:

Q: Four resistors are connected to a battery as shown in Figure P18

Four resistors are connected to a battery as shown in Figure P18.12. (a) Determine the potential difference across each resistor in terms of Ñ”. (b) Determine the current in each resistor...