1. Warm Up 1/13
A 2500 kg car with an initial velocity of 20 m/s is slowed by a 6250 N braking force. What is the car’s velocity after 2.5 seconds?

2. Warm Up 1/14
Right before a 0.05 kg egg hits a collision device, it is traveling at 7 m/s. If the force required to break it is 25 N, what is the minimum amount of time it must have to slow down?

3. Warm Up 1/15
A pitcher throws a kg baseball with as much momentum as a kg bullet moving at 1500 m/s. How fast must the ball be going?

4. Warm Up 1/19
A boy holds his 8 kg puppy on a 2 kg skateboard, initially at rest. He tosses the puppy gently to his friend with a speed of 3 m/s. If the boy and the skateboard move backwards at 0.6 m/s, what is the boy’s mass?

5. Warm Up 1/20
A 2 kg piece of putty collides with a 10 kg bowling ball initially at rest. If their combined speed is then 1.5 m/s, how fast was the putty moving before the collision?

6. Warm Up 1/25
A 44 kg student on a skateboard holds a 22 kg exercise ball. She throws the ball and it causes her to move backwards at 3.5 m/s. What is the velocity of the ball?

7. Warm Up 1/26
A 2 kg piece of putty moving at 8 m/s has collides with a 6 kg bowling ball at rest. What is the change in kinetic energy?

8. Warm Up 2/1 Consider the following objects moving in circles:
A car traveling around a circular ramp on the highway
A ball tied to a string being swung in a circle
The moon as it travels around Earth
A child riding rapidly on a playground merry-go-round
For each example above, answer the following:
Is the circular motion caused by a force?
If so, in what direction is that force acting?
What is the source of the force acting on each object?

9. Warm Up 2/2
A bicyclist rides at a tangential speed of 13.2 m/s around a circular track. The centripetal force is 377 N and the mass of bike and rider is 86.5 kg. What is the radius of the track?

10. Warm Up 2/3
Why did the water stay in the cup when swung around in a circle? If it is going in a circle fast enough then you will be pulling the bucket down faster than gravity is pulling the water down so the water is left behind in the bucket and doesn't fall out.

11. Warm Up 2/4
A banked curve road is built in an area that frequently has icy (almost friction-less) roads.
If the radius of curvature is 150 meters and the angle of embankment relative to the horizontal is 12°, what would be the maximum speed a car could travel at to maintain its circular path? (Assume no friction between tires and road.)

12. Warm Up 2/5
How do ocean tides occur?

13. Warm Up 2/8
Calculate the force of gravity between two students, one with a mass of 65 kg and another with a mass of 83 kg. They are sitting 0.5 meters apart.

14. Warm Up 2/10
A 260 kg satellite orbits a planet with a mass of x 1024 kg at an orbital distance of 6.41 x 106 m. What is its orbital speed?

15. Warm Up 2/18
What is the difference between a hot cup of coffee and a cold cup of coffee at the molecular level?

16. Warm Up 2/22
Does ice water or an equal quantity of hot chocolate have greater internal energy? Why? Will this energy change over time?

17. Warm Up 2/23
What are the differences between Temperature, Heat and Internal Energy?

18. Warm Up 2/25
Why do you feel cool when getting out of a warm swimming pool on a hot day?
How do you feel if it is windy out? Why?
How do you feel if it is an indoor pool? Why?

19. Warm Up 3/1
Why does the sand on the beach burn your feet while the ocean water is cold?

20. Warm Up 3/2
A 20 gram piece of metal at 38°C was placed in .01 kg of water at 9°C. Their final temperature was 15°C. What is the specific heat capacity of the metal? (cp,water= 4186 J/°C*kg)

21. Warm Up 3/3
What is the latent heat required to turn liquid water into steam?

22. Warm Up 3/7
Imagine a small balloon filled with air at room temperature. Suppose you are holding the balloon in both hands, and you squeeze it into a smaller volume.
Has any work been done? Explain.
Has heat been transferred into or out of the balloon? Explain.
Has the internal energy of the balloon changed? Explain.

23. Warm Up 3/8
An engine cylinder has a cross-sectional area of m2. How much work can be done by a gas in the cylinder if the gas exerts a constant pressure of 7.5 x 105 Pa on the piston and moves the piston a distance of m?

24. Warm Up 3/15
Why does leaving the door to your refrigerator open on a hot day, not make the room cooler?

25. Warm Up 3/16
What is entropy?

26. Warm Up 3/21
What is electricity?

27. Warm Up 3/22
Why can only conductors be charged by induction?

28. Warm Up 3/23 Why are objects charged by friction?
Electrons move from one object to another because of the different materials’ affinity for electrons

29. Warm Up 4/11
Make a sketch of the Electric field for each charge or combination of charges.
How are your sketches similar?
How are they different?
Explain.