Work on a sliding crate.

A worker pushes a 47.0 Kg crate across a level horizontal floor by applying a constant force of exactly 150.0 N at an angle of 23.0 degrees below the horizontal. The crate begins at rest and ends 15.0m from where it started traveling at 2.6m/s

A. What is the work done by the applied force as the crate moves across the floor?

B What is the work done by the friction force as the crate moves across the floor?

C. What is the coefficient of kinetic friction [Uk] between the crate and the horizontal plane?

The Tevatron at Fermilab is a cyclotron capable of producing a maximum energy of 2.0 TeV (2×1012eV). Its

circumference is 6.4 km. (a) How fast would proton be moving in the Tevatron? How large of a magnetic

field is required? (b) Repeat part (a) using electrons instead

of protons.

A series of object are being rotated. The same net torque is being applied to each object. Rank the object in order of the resulting angular acceleration (1=lowest).

( ) A solid disk spinning about its center. Total mass is 0.5M and the radius is 2R.

( )An object consisting of two objects connected by a massless rod. Each object has a mass of 2M and is a distance R from the axis of rotation.

( )A solid disk spinning about its center. Total mass is M and a radius of R.

( )A hoop spinning about its center. Total mass is 2M and a radius of R.

Serena's average serve is about 120 mph! Before you begin you will need to convert that to meters per second. It takes the eye about 100 milliseconds to tell the brain it's looking at the ball. By the time the opposing player is ready to react, she only has 400 milliseconds to do so.

1-According to the Sport Science Video on Serena's serve, how long does it take for the eye to pick up the ball once she hits the serve? Write the time in milliseconds.

2-The opponent to Serena's serve doesn't pick up the ball until it as at the net. How long do they have to react to the serve once it is at this point? Write your answer in milliseconds.

3-Serena's serve is clocked on average at 120 mph. Calculate the impulse (change in momentum) on the ball. Assuming its initial speed is zero m/s and the final speed is 120 mph. Let's change that to m/s. The mass of tennis ball is approximately 0.06 kg.

4-If Serena's racket is in contact with the ball for .005 seconds, what is the average force she hits the ball during her serve? This calculation is in Newtons.

5-What is the acceleration of the tennis ball? In m/s^2

Find the magnitude and direction of the resultant of two concurrent forces of 50 and 75 N acting on a body at angle of 50 degrees with each other Use the graphical method and the algerbraic method

For the two state paramagnet, explain why the magnetization M approaches zero at high temperatures.

Suppose the electric field between the electric plates in the mass spectrometer of Figure 27-33 in the textbook is 2.64×104 V/m and the magnetic fields are B=B′=0.36T. The source contains carbon isotopes of mass numbers 12, 13, and 14 from a long dead piece of a tree. (To estimate atomic masses, multiply by 1.66×10−27kg.)

How far apart are the lines formed by the singly charged ions of each type on the photographic film?

What if the ions were doubly charged?

​​​​​Explain the principle and construction of a hydrometer. What is the purpose of the common measurements of the specific gravities of an automobile’s radiator coolant and battery electrolyte?

The potential energy shared by two atoms separated by a distance r in a diatomic molecule is given by the Lennard-Jones function (?0 and ?0 are constants): ?(?) = ?0 [( ?0/?)^12 − 2( ?0/? )^6 ] (a) Where is ?(?) = 0? (b) Show that the minimum potential energy is −?0 and that it occurs at ?0. (c) Where is ?? = 0 ? (d) Sketch ?(?).

Questions for my lab:

What is the significance of the observation of discrete spectral lines in the emission spectrum of hydrogen?

What is the possible effects due to the adjustment of the spectrometer in a hydrogen spectrum?

What is the possible effects due to the orientation of the grating in a hydrogen spectrum? Thanks

In the Olympic shot-put event, an athlete throws the shot with an initial speed of 12.0m/s at a40.0? angle from the horizontal. The shot leaves her hand at a height of 1.80 m above the ground

A.How far does the shot travel?

B. Repeat the calculation of the first part for angle 42.5

C. Repeat the calculation of the first part for angle 45

?

D. Repeat the calculation of the first part for angle 47.5

?

E. At what angle of release does she throw the farthest
?

1.                             Celeste Orion, an assistant coach for The Vanishing Planet Soccer Team has been asked to evaluate each of the team’s players to determine which players kick with the highest velocity. Celeste borrows a radar gun from her friend Pluto. She gathers the players together and asks them to stand at the penalty mark and kick the ball into the goal as hard as they can. She tells them that the ball must go into the goal for it to be considered “legal”. She stands, dead center behind the goal, holds the radar gun 4 ft off the ground and points it directly at the penalty mark (slightly downward). She gives each player 3 “legal” kicks and records the highest speed.

The following information may help you answer this question: 1) The radar gun works by sending a “radar” signal (on a straight line) in the direction that it is pointed. The signal then bounces off the object and returns (on a straight line) back to the gun. The change in the rate of the signal return to the radar gun is used to determine ball velocity. 2) You may look online for the term “cosine effect” in the context of a radar gun.

a. From a purely biomechanical standpoint, explain the limits to her strategy.

b. Give a mathematical example that illustrate the limitations.

c. Identify a simple strategy (or strategies) that she might use to improve her analysis.

What is the difference between static and kinetic friction. Define both, write their SI unit and dimension. Write down the mathematical statement (formula) that allows us to calculate the force of friction. Explain each term with its unit. Let’s say you’re dragging a 50 kg rubber box on wetconcrete. How do you calculate the force of friction on this box?

Consider an old-fashioned bicycle with a small wheel of radius 0.51 m and a large wheel of radius 0.8 m. Suppose the rider starts at rest, accelerates with a constant acceleration for 8 minutes to a velocity of magnitude 24.5 m/s. He maintains his velocity for 9.5 minutes and then decelerates, with constant deceleration, for 7.3 minutes. Find the total angle through which a point on the small wheel has turned.