A 2 kilogram rock is a the edge of a cliff 20 meters above a lake. The rock becomes loose and falls toward the water below. What is the potential energy of the rock at the top? What is the kinetic energy at the top?

What is the potential enery of the rock half way down?

What is the kinetic energy of the rock half way down if the velocity at that point is 14 m/s?

According to social exchange theory, altruistic behaviors benefit the individual who performs them. t/f

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

For problems 1-3, consider a simple dc brush motor with a permanent magnet stator. with an an consider a simple dc brush motor with a permanent magnet ae supply voltage of 100 v, the no-load speed of the motor is 1000 rpm. this motor can provide a torque of 1.9 n-m at 800 rpm drawing a current of 2 a current are both zero at no load.) 1. with an armature supply voltage of 100 v, the motor is operated at 900 rpm. what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input? what is the energy efficiency of the motor? with an armature supply voltage of 100 v, the motor is operated at 1100 rpm (where it acts as a generator). what torque input is required? what mechanical power is required what current is generated? what is the electrical power generated? what is the energy efficiency of the motor acting as a generator? 2. with an armature supply voltage raised to 120 v, the motor is operated at 1000 rpm. what is the no-load speed? what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input what is the energy efficiency of the motor? 3.