Two pucks collide on an air hockey table. Puck A has a mass of 17.0 g and is initially traveling in the +x direction at 7.30 m/s. Puck B has a mass of 51.0 g and is initially at rest. After the pucks collide, puck A moves away at an angle of 42.0 degrees above the +x axis, while puck B travels at an angle of 38.0 degrees below the +x axis.

1. Calculate puck A's final speed.

2. Calculate puck B's final speed.

3. What fraction of kinetic energy was lost in this collision?

A 45 lb. child enjoys swinging very high. If the length of the chain that holds the swing is 2.5 M, approximately how often should the child be pushed to get a good, high swing? Hint: determine the natural frequency for the child.

1. Under what conditions of wind, radiation, air temperature, and hu- midity would you expect the leaf temperature to depart most from the air temperature in a positive direction (leaf hotter than the air) and negative direction (leaf cooler than the air)?

A 200-lb man walks up an inclined plank of negligible weight which makes an angle of 70o with the wall. The coefficient of static friction between the floor and the ladder is 0.3 and that between the ladder and the wall is 0.2. When the man is at a horizontal distance X from the foot of the plank, the plank would begin to slide. (a) Draw a complete FBD of the system. Find (b) the frictional force on the floor, (b) the frictional force on the wall and (c) the horizontal distance X

You’re an accident investigator at a scene where a drunk driver in a 2300 kg car has plowed into a 2000 kg parked car with its brake set. You measure skid marks showing that the combined wreckage moved 27 m before stopping, and you determine a frictional coefficient of 0.74. What do you report for the drunk driver’s speed just before the collision?

Describe the factors (qualitatively and quantitatively) that affect the magnitude of an induced current.

How much internal energy E_int is in the air in a 10 m *10 m * 10 m room at standard temperature and pressure? ( answer: 2.5 * 10⁸ J)

A satellite is being designed to completely orbit the Earth 4 times per day. At what velocity must this satellite have in order to keep the orbit circular? Take the mass of the Earth to be

5.97×1024 kg.

A uniform disk with mass m = 9.44 kg and radius R = 1.32 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 318 N at the edge of the disk on the +x-axis, 2) a force 318 N at the edge of the disk on the –y-axis, and 3) a force 318 N acts at the edge of the disk at an angle θ = 35° above the –x-axis.

3) What is the magnitude of the torque on the disk about the z axis due to F₃?

6)

What is the z-component of the net torque about the z axis on the disk?

7)

What is the magnitude of the angular acceleration about the z axis of the disk?

8)

If the disk starts from rest, what is the rotational energy of the disk after the forces have been applied for t = 1.8 s?

A 6.3 kg block with a speed of 4.8 m/s collides with a 12.6 kg block that has a speed of 3.2 m/s in the same direction. After the collision, the 12.6 kg block is observed to be traveling in the original direction with a speed of 4.0 m/s. (a) What is the velocity of the 6.3 kg block immediately after the collision? (b) By how much does the total kinetic energy of the system of two blocks change because of the collision? (c) Suppose, instead, that the 12.6 kg block ends up with a speed of 6.4 m/s. What then is the change in the total kinetic energy?

Polarization, namely the filtering of non-polarized light waves (the direction of the vibrations of the electric field randomly) into one axis can occur by absorption, reflection, scattering, briefly describing the differences in the three, and examples

If the mass of a Boeing 747 is 183,025 kg and a space shuttle is 2,030,000 kg, use the specific

heats to explain why aluminum or aluminum composites are the preferred metal for building

these machines if the temperatures they are subjected to range from -54 °C to 150 °C for planes

and -121°C to 1649°C for space shuttles. The specific heats of Fe is 449 J/kg*K, Ti is 523 J/kg*K,

Al is 897 J/kg*K, and carbon fiber composites are 2020 J/kg*K. Why aren’t carbon fiber

composites preferred?

SIX quick question! thankyou SO MUCH

1.

A plastic rod, initially uncharged, is rubbed with wool that is also uncharged and obtains a charge of -10 C. What is the charge on the wool after rubbing?

2.

You observe a vibrating string that is anchored between two walls to have seven modes. How many antinodes does the string have?

3

What is alike when the term "two like charges" is used?

4

How do two differently signed charges interact?

5Two sources produce identical sound waves. If one of the sources produced sound that is completely out of phase with the other, what would be the beat frequency you hear?

6

For an infinite sheet of positive charge, the electric field lines:

Nanoparticles interact with light and show Rayleigh scattering and absorption phenomena. Describe essential differences between the two phenomena, especially consider the wavelength dependence in each case?