A quidditch match is going on between Hufflepuff and Ravenclaw. A Hufflepuff chaser is flying 10 degrees north of east at a speed of 5 m/s. A bludger is heading east at a speed of 10 m/s. The bludger has a mass of 10 kg, and the player plus broom has a total mass of 80 kg. If the chaser catches the bludger (i.e. they collide and stick together), at what angle north of east do they move? Give both the expression and the numerical answer. (If you are not familiar with Harry Potter and its wizard jargon, you can reframe the question with the Hufflepuff chaser (player) as a soccer player and the bludger as a soccer ball.).

Please every step of the expression

A bullet of mass 0.0016 kg moving at 499 m/s impacts a large fixed block of wood and travels 6.7 cm before coming to rest. Assuming that the deceleration of the bullet is constant, find the force exerted by the wood on the bullet.

Answer in units of kN

A 4.1 kg bucket of water is raised from a well by a rope. The acceleration of gravity is 9.81 m/s^2 .
If the upward acceleration of the bucket is 2.1 m/s2 , find the force exerted by the rope on the bucket of water.
Answer in units of N

A) The potential energy (U) of an object of mass m at a distance R from the center of the earth can be expressed as, U= -GMm/R. Where is the reference location of potential energy and what is the value of potential energy at that reference location?

B) Write a math expression of total mechanical energy for an object of mass m and escape velocity Vesc at the earth's surface.

C) What is the total mechanical energy of an object of mass m when it reaches at infinity with zero velocity.

D) Derive an expression for escape velocity using your answer in part b and c and calculate it. Mass of earth is 6 * 10^24 kg, radius of the earth is 6.4 * 10^6 m and G= 6.67 * 10^-11 N.m^2/kg.

1. If a closed system loses 2200 J of heat (to the surrounding environment) and 800 J of work is done on the system then what was the change in the internal energy of the system.

2. An ideal gas (inside a cylinder fitted with a movable piston) is heated and slowly expands at constant pressure of 5 atm from 1.5 L to 5.5 L.  How much work is done by the gas in this process?

3. If 1,700 J of heat was added to the gas in problem 3, then how much did the internal energy of the system change?

4. What is the efficiency of an automobile engine that has a heat input of 60.0 kJ and a heat output of 25.0 kJ?

5. If the exhaust temperature of the engine in problem 5 is 250° C, then what is the intake temperature?    (The exhaust and intake temperatures are the low and high operating temperatures of the engine, T_L and T_H)

1. In an isobaric compression of an idea gas, a) the internal energy of the gas remains constant,    b) no heat flows into the gas, c) no work is done on the gas, d) work is done on the gas,        and/or e) work is done by the gas.

2. An ideal gas undergoes an isothermal expansion from one state to another.  In this process determine the following (using the sign conventions on page 413):
   • Q = 0, Q > 0 or Q < 0
   • W = 0, W > 0 or W < 0
   • ΔU = 0, ΔU > 0 or ΔU < 0

3. An ideal gas undergoes an isothermal process.  Which of the following are true (may be more than one):  a) No heat is added or removed from the gas, b) the internal energy of the gas does not change and/or c) the average kinetic energy of the molecules does not change.

4. An ideal gas undergoes an adiabatic expansion in which no heat flows into or out of the gas.  As a result determine which of the following properties of the gas increases (may be more than one): a) temperature, b) pressure and/or c) volume.  

5. Can you cool your kitchen by leaving your refrigerator door open?  Why or why not?

6. If 1500 J of heat is added to a system and the system does 1100 J of work, then what was the change in the internal energy of the system?   Assume the system is closed (i.e. a gas inside of a cylinder fitted with a movable piston).

Write the three Newton’s Laws of motion and give one example for each Law:

Newton’s First Law:

Newton’s second Law:

Newton’s Third Law:

b)What is the difference between elastic and inelastic Collison in terms of total momentum and total kinetic energy ?

1) For a concave mirror at what object distance does the associated image transition between upright and inverted?

2) As the object distance increases through the distance you answered in part one does the image transition from upright to inverted or from inverted to upright?

3) For object distances slightly less than the distance you answered in part one is the image location near or far from the mirror and is it in front of or behind the mirror?

4) For object distances slightly more than the distance you answered in part one is the image location near or far from the mirror and is it in front of or behind the mirror?

5) For distances near to the distance you answered in part one is the image reduced or enlarged and is it reduced or enlarged by a small or large amount?

6) Which type of lens exhibits a similar behavior, converging or diverging?

A.

What is an electrical transformer? Discuss basic principles of operation and applications of electrical transformers. Can you relate electromagnetic induction to the operation a transformer?

B.

Discuss similarities and differences between RL and RLC Circuits. How can one tell if an RLC circuit is underdamped or overdamped? What are some applications of RLC Circuits?

My Notes

A 5000-kg freight car rolls along rails with negligible friction. The car is brought to rest by a combination of two coiled springs as illustrated in the figure below. Both springs are described by Hooke's law and have spring constants with

k₁ = 1700 N/m

and

k₂ = 3200 N/m.

After the first spring compresses a distance of 33.0 cm, the second spring acts with the first to increase the force as additional compression occurs as shown in the graph. The car comes to rest 49.5 cm after first contacting the two-spring system. Find the car's initial speed.

You are to explain why a baseball can be made to curve in flight according to the appropriate concepts presented in Biomechanics. use terms like magnus force, lift, bernouli principle.

Please select all that are correct.

Select one or more:

a. If two trucks (same model) are driving with the same velocity, the empty truck has less momentum than the truck fully loaded with rubber ducks

b. Law of conservation of momentum only works in 1D and 2D, but no higher

c. A snowball is thrown on a wall. It bounces off, but leaves a white mark behind. This is neither a perfect elastic collision, nor a perfect inelastic collision

d. Halving the time the force is applied on an object doubles the impulse

e. When the law of conservation of momentum is concerned, a pile of sand cannot be used as a closed system because the grains of sand do not stick together and there are too many of them

f. If a cup of hot coffee is defined as a closed system, then the steam coming off the surface has to be accounted for as part of the system

g. Having a pie thrown on one's face is an example of an inelastic collision

h. Velocity, momentum, and impulse can all be expressed in terms of their x-, y-, and z- components

i. When two figure skaters (one going SouthEast, the other going NorthEast) clasp hands, they begin moving West before

A 456 g oscillator has a speed of 98.0 cm/s when its displacement is 3.00 cm and 69.0 cm/s when its displacement is 5.30 cm.

What is the oscillator's maximum speed?

If you increase the potential difference or electromotive force across a resistance in a circuit the current flowing through that device will___.

Question 8 options:

A proton starts on a plate with potential of 5.0 x 10^3 V at y=0m. It then enters a region in which there is magnetic field of 2.0 T pointing out of the page. In a field it travels a semicircular path.

a) what is the radius of the semicircle

b)where (what value of y) doed the proton leave the magnetic field?

c) the proton now passes between a second set of plates with a potential difference of 5 x 10^3 V. What is its velocity after passing through these plates?

d) The proton now enters another region in which there is a magnetic field of 2.0 T pointing out of the page, and it again describes a semicircular path. What is the radius of the semicircle

e) where (what value of y) does the proton emerge from the field now?