An ice hockey puck is tied by a string to a stake in the ice. The puck is then swung in a circle. What force is producing the centripetal acceleration of the puck? a. Tension in the string.
b. Air resistance.
c. Normal force.
d. Gravity.
e. Friction.

Asubmarine has a "crush depth" (that is, the depth at which water pressure will crush the submarine) of 250 m. what is the approximate pressure (water plus atmospheric) at this depth? (recall that the density of seawater is 1025 kg/m3, g = 9.81 m/s2, and 1 kg/(ms2) = 1 pa = 9.8692 10-6 atm.) a. 34.8 atm b. 24.8 atm c. 25.8 atm d. 7.8 atm

What is the efficiency of an engine that does 80 j of work and exhausts 320 j of heat while taking in 400 j of heat ? a. 10% b. 20% c. 80% d. 25%

An object with a mass of 1.5 kg changes its velocity from + 15 m/s to +22 m/s during a time interval of 3.5 seconds. what impulse was delivered to the objects?