A red car and a blue car are driving in the same direction on the interstate. The red car is travelling at 25 m/s, while the blue car is travelling at 35 m/s. The driver of the blue car is not paying attention and rear-ends the red car. The red car has a mass of 2,000 kg while the blue car is only 1,000 kg.

A Prior to the collision, what is the value of the center of mass kinetic energy?

B. In order for this collision to be isolated, what is the maximum amount of energy that can be converted to other forms during the collision? What percentage of the initial kinetic energy does this represent?

C. If the system loses 40% of its kinetic energy in the collision, is the system isolated? Why or why not?

D. Prior to the collision, how fast and in what direction would you need to be travelling in order for the system to appear to have zero momentum?

E. Regardless of your answer to part (c), assume now that the two vehicles form an isolated system. If they cars stick together, how fast will they be moving?

F. What minimum amount of kinetic energy must be conserved in order to conserve the momentum of the system?

Using a 685 nm wavelength laser, you form the diffraction pattern of a 0.119 mm wide slit on a screen. You measure on the screen that the 11th dark fringe is 9.47 cm away from the center of the central maximum. How far is the screen located from the slit?

1. What can you say in general about the effect of wire/string thickness in some instruments on the produced frequencies?

why does it seem always windier in the city?

In an emergency stop, a shoulder- strap seat belt holds a 60 kg passenger firmly in place. The car was initially traveling at 30 m/s and came to a stop in 6.0 seconds along a straight, level road. What was the average force applied to the passenger by the seatbelt?

Determine the magnitude of the force between two parallel wires.

Express your answer to two significant figures and include the appropriate units.

How many hours would be required to make a 3900 km trip across the United States if you average 100 km/h? ______h

At an average speed of 145 mph, how long would it take a race car to complete a 680 mile race? ____h

A certain car can accelerate from 0 to 60 mph in 7.5 s. What is the car's average acceleration in mph/s? _____ mph/s

You throw a ball straight up at 20 m/s. How many seconds elapse before it is traveling downward at 12 m/s? _____s

A rock is dropped into an abandoned mine and a splash is heard 8 s later. Assuming that it takes a negligible time for the sound to travel up the mine shaft, determine the depth of the shaft and how fast the rock was falling when it hit the water. depth of well ________ m velocity of rock __________ m/s

A football player kicks the ball so that it will have a "hang time" (time of flight) of 5.0 sec and land 50m away. If the ball leaves the player's foot 0.5 m above the ground,

(a) find the initial velocity of the ball

(b) find the velocity of the ball when it lands on the ground

A student has two lenses, one of focal length 5.5 cm and the other with focal length 15 cm.

Find the maximum magnification produced by each of these lenses.

M1, M2?

In the sigma-model of spontaneous symmetry breaking, we have degenerate vacuum states. But if we don't pick up a particular value of VEV, we won't have any symmetry breaking. As I read from a book, in field theory at finite volume, there would be no problem; but at infinite volume, we are forced to choose a value of the ? field. But why?

A ball is thrown straight up from the edge of the roof of a building. A second ball is dropped from the roof a time of 1.16 s later. You may ignore air resistance.

a. If the height of the building is 19.0 m , what must the initial speed be of the first ball if both are to hit the ground at the same time?

b. Consider the same situation, but now let the initial speed v0 of the first ball be given and treat the height h of the building as an unknown. What must the height of the building be for both balls to reach the ground at the same time for v0 = 9.00 m/s .

c. If v0 is greater than some value vmax, a value of h does not exist that allows both balls to hit the ground at the same time. Solve for vmax.

d. If v0 is less than some value vmin, a value of h does not exist that allows both balls to hit the ground at the same time. Solve for vmin.

Taking the density of air to be 1.29 kg/m³, what is the magnitude of the linear momentum of a cubic meter of air moving with the following wind speeds?

a)    15 km/h

b) 74 mi/h—the wind speed at which a tropical storm becomes a hurricane

A 5-m-long cylinder of solid aluminum has a radius of 2 cm.

(a) If the cylinder is at a temperature of 0 °C, how much will the length change when the temperature rises to 50 °C?
  m

(b) Due to the temperature increase, by how much would the density of the aluminum cylinder change?

The density decreases by  % upon heating.

(c) By what percentage does the volume of the cylinder increase?

The volume increases by  % upon heating.

A golfer hits a shot to a green that is elevated 2.50 m above the point where the ball is struck. The ball leaves the club at a speed of 17.8 m/s at an angle of 50.0˚ above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air resistance, find the speed of the ball just before it lands.

If you have a bowl of ice that's melting, so the ambient temperature is just above 0