Motion
Which of the following is an example of motion with constant velocity?
a) a car that comes to a stop at a stop sign
b) an object moving in a circle with a constant speed
c) a car that drives with constant speed up and over a hill and then down the other side
d) a box sliding with a constant speed down a ramp
d) a box sliding with a constant speed down a ramp
What is potential energy?
Energy that is stored for later use
What is the first law of thermodynamics?
Energy can be neither created nor destroyed, only altered in form. The change in thermal energy equals the added to the system minus the work done by the system.
How much time does it take for a car to come to rest if it has an initial speed of 22 m/s and slows with a deceleration of 6.1 m/s2?
3.6 s
An intern pushes a 72-kg patient on a 15-kg gurney, producing an acceleration of 0.60 m/s2. How much work does the intern do by pushing the patient and gurney through a distance of 2.5 m?
130 J
Jogging in the park, you do 4.3 x 105 J of work and give off 3.8 x 105 J of heat. What is the change in your thermal energy?
-8.1 x 105 J
You throw a baseball upward with an initial velocity of 8.2 m/s. Gravity gives the ball a downward acceleration of -9.81 m/s2. What is the velocity of the ball 1.5 s after it was thrown?
-6.5 m/s
Find the gravitational potential energy of a 65-kg person sitting on a diving board that is 3.0 m high.
1900 J
What is the second law of thermodynamics?
The total entropy of a system remains constant in any spontaneous process, it never decreases