Physics Homework
ernesto.gonzalez
Homework2.docxHOMEWORK II Free Response
Name: __________________________________________________ ID: ____________________
Instructions:
You should have 5 numbered pages on the exam, please check and let me know if you are missing any. Please for all purposes use 10 m/s2 as the value for the gravitational acceleration.
Free-Response Section: For this part there are three problems, please make sure to show all your work.
Warning:
Use notation other than the one used in class or your text question will be INVALIDATED.
Upon completion submit your solutions as word or pdf format documents only. NO other file will be accepted.
Academic Integrity:
Giving assistance to or receiving assistance from another student or using unauthorized materials during a test can be grounds for disciplinary action, up to and including expulsion.
Problem 1: A two mass system with friction.
The picture below shows a 2kg empty bucket pulling on 10 kg block at rest on a rough table. The coefficients of friction are .8 and .4 respectively. You start to add rocks to the bucket until it breaks into motion.
· At the moment that the system starts to move, draw the free-body diagram for the two objects. Draw the block FBD to the left and the bucket FBD to right of the picture
· Calculate the mass of the rocks added to the bucket;
· Determine the accelerations of the bucket once it starts to move; and
· How long would it take the block to fall of the table, if it is 1.5m from the edge at the moment it starts to move?
Problem Two: A motor cycle:
A motorcycle traveling at constant speed of 36 Km/h passes over the top of a hill whose radius of curvature is 100 m . The mass of the motorcycle and driver is 150 Kg.
· Sketch the situation and label the forces acting on the motorcycle; Create a free body diagram for the moment the motorcycle is at the top of the hill.
· Determine the centripetal force on the motorcycle when it is at the top of the hill;
· Determine the normal force on the motorcycle?
Problem Three: Satellite orbiting Earth.
A 5000 kg satellite orbits the Earth at an altitude of 3000 Km. Knowing that the mass and radius of the Earth are 5.98 x 10^24 Kg and 6.38x10^3 Km respectively, and
G=6.67x10^-11 (N. m^2)/Kg^2 , calculate the following quantities:
· The force of gravity on the satellite;
· The gravitational acceleration at the satellite orbit;
· The time it takes the satellite to complete one revolution about the Earth; and
· The orbital speed of the satellite.
