1. Recent Virginia Election

2. Day 8, Physics 131

3. Yes, regularly scheduled physics tutoring for June 2015 is here!
Physics Tutoring Sessions Term I (June)
Monday:       4:00-6:00 pm, RRO 119 (Dylan Cromer) Tuesday:      3:00-4:30 pm, RRO 119 (Gaither Frye) Wednesday: 4:00-6:00 pm, RRO 119 (Dylan Cromer) Thursday:     3:00-4:30 pm, RRO 119 (Gaither Frye)

4. HW Problem 9-5 A 0.150-kg baseball is dropped from rest.
The magnitude of the baseball’s momentum is kg m/s just before it lands on the ground.
? From what height was it dropped. ?

5. HW Problem 9-16
When striking a volleyball, a player changes the velocity of the ball from 4.2 m/s to -24 m/s along a certain direction.
? If the impulse delivered to the ball is -9.3 kg m/s, what is the mass of the volleyball?

6. HW Problem 9-24
An object initially at rest breaks into two pieces as the result of an explosion. One piece has twice the kinetic energy of the other piece.
? What is the ratio of the masses of the two pieces ?
? Which piece has the larger mass ?

7. HW Problem 9-34
A kg block is attached to a horizontal spring that is at its equilibrium length.
Force constant k of spring is 20.0 N/m.
Block rests on frictionless surface.
A kg wad of putty is thrown horizontally at the block, hitting it with a speed of 2.30 m/s and sticking.
? How far does the putty-block system compress the spring ?

8. HW Problem 9-37
A 732-kg car stopped at an intersection is rear-ended by a 1720-kg truck moving with a speed of 15.5 m/s.
? If the car was in neutral and its brakes were off, so that the collision is approximately elastic, find the final speed of both vehicles after the collision ?

9. HW Problem 9-45
See figure for a stack of three bricks, each of mass m and length L.
? Find the x coordinate of the center of mass of the bricks. ?

10. HW Problem 9-51, Pizza!
The location of the center of mass of the partially-eaten 12-inch-diameter pizza shown in the figure is Xcm = -1.4 in. and Ycm = -1.4 in.
Assume that each quadrant of the pizza is the same.
? Find the center of mass of the uneaten pizza above the x-axis (that is, the portion of the pizza in the second quadrant) ?

11. HW Problem 9-60
A 57.8-kg person holding two kg bricks stands on a 2.10-kg skateboard. Initially, the skateboard and the person are at rest. The person now throws the two bricks at the same time so that their speed relative to the person is 17.0 m/s.
?What is the recoil speed of the person and the skateboard relative to the ground, assuming the skateboard moves without friction.?

12. HW Problem 9-71
A 1.35-kg block of wood sits at the edge of a table, m above the floor.
A kg bullet moving horizontally with a speed of 715 m/s embeds itself within the block.
? What horizontal distance does the block cover before hitting the ground ?