a) You wish to melt a 3.0-kg block of aluminum, which has already been heated to 660ºC. How much heat is required to melt the aluminum? (the textbook lists the latent heat of aluminum as 396,000 J/kg)

b) You wish to melt a 3.0-kg block of aluminum, which initially at 20ºC. How much heat is required to melt the aluminum? (the textbook lists the latent heat of aluminum as 396,000 J/kg)

A neutron combines with a carbon nucleas in an elastic collision. The carbon is at rest and the neutron travels at a speed of 2.6x10^6 m/s. The mass of carbon nucleus is 12 times the mass of neutron. Determine the velocities of the carbon nucleas and the neutron after collision.

1. Standby power (sometimes called vampire power) is the power used by a device that is off but plugged in and in a standby mode. Regulations typically limit this power to 1 Watt. If electricity costs $0.10 per kilowatt-hour, then to the nearest order of magnitude, and assuming 1 Watt, how much does it cost to leave a device in standby mode for one year?

(A) $0.01

(B) $0.10

(C) $1.00

(D) $10.00

(E) $100.00

Water makes life possible as a solvent for biological molecules. What electrical properties allow it to do this?

1. A collision in which two bodies remain joined together after the collision is referred to as.

2. A 0.5 kilogram cart moving at 0.360 m/s has how much momentum

3. If the 0.5kg cart moving at 0.36 m/s was to hit a barrier and bounce back with a velocity of - 0.240 m/s, what is its change in momentum

4.How fast must a 0.25 kg cart be traveling to have a momentum of 0.450 kgm/s?

5. A 0.230 kg baseball is thrown with a speed of 41 m/s. If the ball comes to rest in the catcher’s mitt in 0.085 seconds, how much force does the ball apply on the catcher’s mitt? (hint: use the impulse-momentum theorem )

6. Imagine you are ice skating with your friend. Both of you are at rest, when you shove him/her away from you. You have a mass of 65 kg and he/she has a mass of 55kg. When you shove off, you move away with a velocity of 2.0 m/s. With what velocity does your friend move away from you?

7. If a 0.25 kg cart moving to the right with a velocity of +0.31 m/s collides inelastically with a 0.5 kg cart traveling to the left with a velocity of - 0.22 m/s, what is the total momentum of the system before the collision?

8. What is the resulting velocity of the above two-car system (stuck together)?

A 5.80-g lead bullet traveling at 600 m/s is stopped by a large tree. If half the kinetic energy of the bullet is transformed into internal energy and remains with the bullet while the other half is transmitted to the tree, what is the increase in temperature of the bullet?

Answer in degrees celcius

PLEASE EXPLAIN ALL STEPS.

How does the Doppler effect aid police in detecting speeding motorists?

A 2.40-m-long pulse is travelling at a speed of 5.75 m/s in a spring. How long does it take the pulse to pass any point on the spring?

A 30.0-g object moving to the right at 20.5 cm/s overtakes and collides elastically with a 11.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. (Take the positive direction to be to the right. Indicate the direction with the sign of your answer.)

8. You begin to get tired and the book begins to slide down. The book begins to slide down, and you respond so it slides down at a constant velocity. How do each of the forces you have identified change from their magnitudes in part (a)? Explain how you know. (this question will not be auto-graded, answer fully)

9. If the book has a mass of 2 kg, the coefficient of friction between the sliding book and the wall is 0.4, how hard do you have to press on the book if it is sliding down with a speed of 2 cm/s? D2M

10. BCD on 9

One non-powered sled is sliding over a snowed surface, first down from the top of a flat and inclined plane using only gravity and no initial speed and then it continues to move along a horizontal surface until a full stop. The plane’s surface is inclined with 45 degrees relative to the horizontal. The top of the inclined plane is 2 meters high relative to the same horizontal surface. The friction coefficient between the sled and snow is 0.05 on all surfaces. Draw the free-body diagrams and determine the formula and the value for the distance made by the sled onto the horizontal surface.

Draw the Free-body diagrams as well

Identify the synthesis method that has the best chance to yield nanoparticles of a uniform size. For comparison, also identify which method we covered that you believe is the least likely to yield uniformly sized particles. Explain your reasoning for selecting these two.

Think of a Newtonian cradle made of only two marbles. These two marbles of masses m1 and m2 are each suspended by identical strings. The strings are initially both vertical so the marbles are touching each other when undisturbed. The marble with m1 is shifted away from the initial position until is reaching the height h1 while the length of the string does not change and then is set free to fall and collide with marble m2. What is the formula for the height which both marbles will reach after the collision if: a). The collision is elastic; b). The collision is inelastic; (c). What will be the heat developed during the collision in both cases?Hint: when the marbles collide, all vectors velocity are orientated along the same axis.

Draw diagrams as well

Assume a galaxy forms its stars in a single rapid burst, with a Salpeter initial mass function extending from 0.1 to 100 Msun. After 10 Gyrs have passed, divide the surviving stars into three groups: lower main-sequence upper main sequence (MS stars with mass > 0.75 Msun), lower main sequence (MS stars with mass < 0.75 Msun), and red giants. Calculate the fractional contribution of each group to: 


(a) the total number of surviving stars. (b) the total mass in surviving stars. (c) the total luminosity of the galaxy.

Hints: Assume the MS lifetime-vs-mass relation and RGB lifetimes as given in Lecture I. Ignore post-RGB evolutionary stages. For MS stars, assume luminosity-mass relation of (L/Lsun) = (M/Msun)3.5. Assume (crudely) that the average RGB luminosity is ~100 times higher than the turn-off luminosity.