Which of the following is the best hypothesis? O A. Water and Air would be a good name for a rock band.
B. How much energy do I need to heat 100 g of water from 20°C to 40°C?
O C. More energy is needed to heat 100 g of water than to heat 100 g
of air.
O D. Water is often warmer than air.

Aspring has a natural length of 8 m. if a 12-n force is required to keep it stretched to a length of 10 m, how much work w is required to stretch it from 8 m to 16 m? (round your answer to two decimal places.)

The earth exerts a gravitational force of 500 n on amy. what is amy’s mass in kg?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?