Besides the gravitational force, a 2.50-kg object is subjected to one other constant force. The object starts from rest and in 1.20 s experiences a displacement of (5.40î − 3.30ĵ) m, where the direction of ĵ is the upward vertical direction. Determine the other force.

a. Compute the energy of a photon with incident energy 200 kev scattered at 90°

in a Compton event.

b. Compute the energy of the backscattered photon from a 400 kev incident

photon.

c. Compute the energy of the recoil electron.

QUESTION 1

Engineers wish to launch a satellite from the surface of the Moon. What is the minimum speed the satellite must have to escape the Moon’s gravity – that is, what is the escape velocity at the surface of the Moon? The Moon has a mass of 7.3x10^22 kg and a radius of 1.7x10^6 m.

10 points   

QUESTION 2

The satellite is guided to a circular orbit about the Sun at the same distance from the Sun as the Earth (1.5x10^11 m), but far away from the Earth (so only the Sun’s gravity is important). What is the satellite’s gravitational acceleration due to the Sun, which has a mass of 2.0x10^30 kg?

10 points   

QUESTION 3

The satellite is guided to a circular orbit about the Sun at the same distance from the Sun as the Earth (1.5x10^11 m), but far away from the Earth (so only the Sun’s gravity is important). What is the satellite’s speed?

10 points   

QUESTION 4

The satellite is guided to a circular orbit about the Sun at the same distance from the Sun as the Earth (1.5x10^11 m), but far away from the Earth (so only the Sun’s gravity is important). What is the satellite’s gravitational potential energy if it has a mass of 200 kg? The Sun has a mass of 2.0x10^30 kg.

10 points   

QUESTION 5

The satellite is guided to a circular orbit about the Sun at the same distance from the Sun as the Earth (1.5x10^11 m), but far away from the Earth (so only the Sun’s gravity is important). The satellite is the stopped using orbital thrusters and allowed to fall to the Sun. What is the satellite’s speed when it reaches the surface of the Sun? The Sun has a mass of 2.0x10^30 kg and a radius of 7.0x10^8 m.

Hint: Use energy conservation. First consider the potential energy when it is at the Earth’s orbit, then equate this to the sum of the potential energy at the surface of the sun and the kinetic energy at the surface of the sun.

Internal Resistance of a battery lab

I'm doing this lab where we have to find the internal resistance of a charged and uncharged battery. We got our data by plotting a V vs I graph, and found the internal resistance of each battery using the slopes of the graphs. From my graphs, I can see that the internal resistance of the charged battery is higher than that of the uncharged one. Which makes sense. However, I'm having a hard time writing the conclusion for this lab. The current increases as the voltage decreases for both batteries, which is obvious, what else am I supposed to say? Any comments I can add?

As observed on earth, a certain type of bacteria is known to double in number every 24 hours. Two cultures of these bacteria are prepared, each consisting initially of one bacterium. One culture is left on earth and the other placed on a rocket that travels at a speed of 0.746c relative to the earth. At a time when the earthbound culture has grown to 32 bacteria, how many bacteria are in the culture on the rocket, according to an earth-based observer? Please explain each step and use (delta)t = (delta)to/sqrt(1-(v^2/c^2))

A bicycle tire is spinning counterclockwise at 3.10 rad/s. During a time period Δt = 2.40 s, the tire is stopped and spun in the opposite (clockwise) direction, also at 3.10 rad/s. Calculate the change in the tire's angular velocity Δω and the tire's average angular acceleration α_av. (Indicate the direction with the signs of your answers.)

(a) the change in the tire's angular velocity Δω (in rad/s)

(b) the tire's average angular acceleration α_av (in rad/s²)

(a) What is the magnitude of the tangential acceleration of a bug on the rim of a 12.0-in.-diameter disk if the disk accelerates uniformly from rest to an angular speed of 80.0 rev/min in 3.60 s?
------m/s²

(b) When the disk is at its final speed, what is the magnitude of the tangential velocity of the bug?
------- m/s

(c) One second after the bug starts from rest, what is the magnitude of its tangential acceleration?
----------m/s²

(d) One second after the bug starts from rest, what is the magnitude of its centripetal acceleration?
--------- m/s²

(e) One second after the bug starts from rest, what is its total acceleration? (Take the positive direction to be in the direction of motion.)

A 1 mole, 293 K gas expands isothermally, starting at 22.4 L in volume. What is its final volume? Only solve with variables, not numarically.

1) Describe the basic principles of Fluorescence Correlation Spectroscopy (FCS). What do you measure in an FCS experiments and how do you perform the measurements.

In which situation is mechanical energy conserved?

A. a parachutist descends at constant speed

B. a car slows down without braking along a flat road

C. a heavy crate is raised at constant speed via a rope and pulley system

D. a sled accelerates as it slides down a frictionless inclined plane

____________________

Two spaceships have the same mass. Spaceship A has kinetic energy K and spaceship B has kinetic energy 16K. What is the ratio of their speeds, vA/vB?

A. 1/16

B. 1/8

C. 2/1

D.  1/4

What will be the difference in SIL of the sounds from two loudspeakers, one with an efficiency of 2.1% and one with an efficiency of 10.3%. Assume that all other variables, including the electrical power supplied, are the same in the two cases.

Block 1 (0.5 kg) travels with an initial velocity of [ 40i ] + [ 60j ] m/s and then collides with block 2 (0.5 kg) traveling with an initial velocity of [ -40i ] + [ -40j ] m/s.
After the collision, block 1 has a final momentum of [ 5i ] + [ -25j ] kg*m/s. Assume that no external forces are present and therefore the momentum for the system of blocks is conserved.

What is the initial momentum of block 1?
i +   j kg*m/s

What is the initial momentum of block 2?
i +   j kg*m/s

What is the total initial momentum of the system of blocks?
i +   j kg*m/s

What is the change in momentum for block 1? (notice that you are given the final momentum for block 1.)
i +   j kg*m/s

What is the change in momentum for block 2?
i +   j kg*m/s

What is the final momentum of block 2?
i +   j kg*m/s

What is the total final momentum of the system of blocks?
i +   j kg*m/s

What is the total change of momentum of the system of blocks?
i +   j kg*m/s

What are the initial kinetic energies of block 1, block 2, and the system of blocks?
Block 1:  J
Block 2:  J
System of blocks:  J

What are the final kinetic energies of block 1, block 2, and the system of blocks?
Block 1:  J
Block 2:  J
System of blocks:  J

What is the change in kinetic energy of the system of blocks due to the collision?

Question 1: At a height of ten meters above the surface of a freshwater lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.175 s later. The air and water temperatures are 20 ^oC. How deep is the lake?

Question2: A hunter is standing on flat ground between two vertical cliffs that are directly opposite one another. He is closer to one cliff than the other. He fires a gun and, after a while, hears three echoes. The second echo arrives 1.92 s after the first, and the third echo arrives 1.46 s after the second. Assuming that the speed of sound is 343 m/s and that there are no reflections of sound from the ground, find the distance (in m) between the cliffs.