Which of the following statements are true? A. Mechanical energy is conserved because no dissipative forces perform work on the ball.
B. The forces of gravity and the spring have potential energies associated with them.
C. No conservative forces act in this problem after the ball is released from the spring gun.

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

25pts the diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

Which of the following are guidelines to follow for obtaining accurate observations