1.) assuming the clay blob and the superball have the same mass, and that you throw them with the same velocity, which would you throw to close the door? the clay blob will stick to the door and the superball will bounce back with almost the same speed as it had before it collided with the door. which would be more effective at closing the door - the superball or the clay of the same mass?

2.) what is the final momentum of the clay ball?

3.) how do you find the impulse of a force from the force vs. time graph?

4.) in a perfectly elastic collision between a cart and a wall, the cart would recoil with exaclty the same magnitude of momentum that it had the before the collision. because your cart's spring bumper is not perfect, you can only produce a nearly elastic collision. why is the collision made with a "springy" wall?

5.) from the above question ( question 4) how will you measure the impulse?

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

As a car drives with its tires rolling freely without any slippage, the type of friction acting between the tires and the road is 100) a) static friction. b) kinetic friction. c) a combination of static and kinetic friction. d) neither static nor kinetic friction, but some other type of friction. e) it is impossible to tell what type of friction acts in this situation.

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?