Questions from College Physics

Q: A +2.0 nC point charge is 3.0

A +2.0 nC point charge is 3.0 cm away from a −3.0 nC point charge. (a) What are the magnitude and direction of the 6electric force acting on the +2.0 nC charge? (b) What are the magnitude and directi...

Q: Two metal spheres separated by a distance much greater than either sphere’s

Two metal spheres separated by a distance much greater than either sphere’s radius have equal mass m and equal electric charge q. What is the ratio of charge to mass q/m in C/kg if the electrical and...

Q: Magnetic forces cause an excess of positive ions to flow along one

Magnetic forces cause an excess of positive ions to flow along one side of the artery and negative ions on the opposite side. What is the greatest possible potential difference across the artery?

Q: Prove Eq. (7-24) / .

Prove Eq. (7-24) . [Hint: Start with , where is the net external force acting on a system and / is the total momentum of the system.]

Q: (a) What is the equivalent resistance between points A and

(a) What is the equivalent resistance between points A and B? Each resistor has the same resistance R. (b) What is the equivalent resistance between points B and C? (c) If a 32 V emf is connected to...

Q: A steel rule is calibrated for measuring lengths at 20.00

A steel rule is calibrated for measuring lengths at 20.00°C. The rule is used to measure the length of a Vycor glass brick; when both are at 20.00°C, the brick is found to be 25.00 cm long. If the rul...

Q: In the figure, a third point charge −q is placed

In the figure, a third point charge −q is placed at point P. What is the electric force on −q due to the other two point charges?

Q: An arrangement of two pulleys, as shown in the figure,

An arrangement of two pulleys, as shown in the figure, is used to lift a 48.0 kg crate a distance of 4.00 m above the starting point. Assume the pulleys and rope are ideal and that all rope sections a...

Q: Two point charges are separated by a distance r and repel each

Two point charges are separated by a distance r and repel each other with forces of magnitude F. If their separation is reduced to 0.25 times the original value, what is the magnitude of the forces of...

Q: A K+ ion and a Cl− ion are directly across

A K+ ion and a Cl− ion are directly across from each other on opposite sides of a cell membrane 9.0 nm thick. What is the electric force on the K+ ion due to the Cl− ion? Ignore the presence of other...