Physics Work,Power & Energy Level: Misc Level
Find the work done by a force F of magnitude 300.0 N as it moves through a deisplacement s of magnitude 23.0 m. The angle between F and s is 143 degrees.
Physics Work,Power & Energy Level: Misc Level
According to the law of Conservation of Momentum, in an ideal,isolated system, when two objects collide it does what?
Physics Work,Power & Energy Level: Misc Level
If a brick of mass 13.0 kg is dropped from a height of 45 m above the surface of the earth,what kinetic energy will it momentary possess at 1 m from the ground as it plunges earthwards?
Physics Work,Power & Energy Level: Misc Level
Consider a hockey player skating across the ice 12.0 m/sec. His weight is 800.0 N. what is the kentic energy?
Physics Work,Power & Energy Level: Misc Level
Just before striking the ground, 2.0-kg mass has a kinetic energy of 400 J. Assuming that it was dropped from rest, determine the height from which it was released.
Physics Work,Power & Energy Level: Misc Level
7. During a tennis serve, a racket is given an angular acceleration of magnitude 130 rad/s 2. At the top of the serve, the racket has an angular speed of 12 rad/s. If the distance between the top of the racket and the shoulder is 1.3 m, find the magnitude of the total acceleration of the top of the racket.
Physics Work,Power & Energy Level: University
Spring ForceA railroad freight car of mass M and inital speed v0rolls without friction in the positive x direction (see figure below). The car is brought to rest by a spring bumper with spring constant k on a second freight car with its breaks locked. (a) Find the distance the spring is compressed in terms of M v0 and k. (b) Is the momentum and mechanical energy conserved during the collision? use the correct physics principles to explain your response. (c) Sketch a graph of the potential energy of the spring versus the compression distance of the spring.
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Physics Work,Power & Energy Level: University
Conservation of MomentumThe owners of an amusement park have hired you to determine if their design for a new loop the loop ride is safe. The car has a speed of 5m/s when it located on the tracks at a height h. The car coasts along the track going around the inside of the vertical circle of radius r = 100m. The car is not physically bolted to the tracks but rides on the track in the same way as a railroad car rides on ordinary railroad tracks. The bottom of the circle is at ground level and the schematic drawing of the ride is shown below. The circular tracks have already been constructed and the blueprints speeify a starting height 220m. However the owners are not sure whether this height is well above the minimum height for which the car will stay on the tracks at the top of the circle. You have been consulted before the construction begins on the starting track to determine if this proposed height is safe. The coefficient of friction between the tracks and the wheels is 0.0. (a) What force if any does the track exert on the car at point B? Point C? Identify by name the physics principles you use. Assume that the car has mass 500kg. (b) Will the car remain on the tracks if the blueprints starting height is used? If yes show using the correct physics principle (s). If no find the exact angle where the car leaves the tracks(c). Based on your calculations what would you advise the owners to do? Determine the minimum height h for the car to just stay on the tracks. Use the safer of the two starting heights for all the remaining questions. (d) Determine the velocity of the car when it reaches the bottom of the circle when it reaches point A when it reaches the top of the circle. Identify the physics principles that use. (e) Does the car execute uniform circular motion? Explain. (f) If a 70 kg rider is seated in the car what force does she exert on the seat when the car reaches the bottom of the track? If she were seating on scales what it read at the bottom of the track? Identify the physics principles that you use.
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Physics Work,Power & Energy Level: University
Time PeriodA medical centrifuge is rated at 15000rph. How long will it take the centrifuge to make one revolution?
Physics Work,Power & Energy Level: University
CollisionTwo identical cars hit each other and lock bumpers. In each of the following cases what are the speeds of the cars immediately after coupling bumpers? (a) A car moving with a speed of 90 km/h approaches a stationary car (b) two cars approach each other with speeds of 90km/h and 120 km/h respectively (c) two cars travel in the same direction with speeds of 90km/h and 120km/h respectively.
Physics Work,Power & Energy Level: University
Conservation of MomentumWhen bunting abaseball player uses the bat to change both speed and direction of the baseball (a) will the magnitude of the change in momentum of the baseball before and after the bunt be (1) greater than the magnitude of the momentum of the baseball either before or after the bunt (2) equal to the sum of the magnitude of momenta of the baseball before/ after the bunt? (b) The baseball has a mass of 0.16 kg its speeds before and after the bunt are 15m/s and 10m/s respectively and the bunt lasts 0.025s. What is the change in momentum of the baseball? (c) What is the average force on the ball by the bat?
Physics Work,Power & Energy Level: University
Onlique CollisionA 0.20 kg billiard ball traveling at a speed of 15m/s strikes the side rail of a pool table at an angle of 60 degrees. If the ball rebounds at the same speed and angle what is the change in its momentum?
Physics Work,Power & Energy Level: University
Conservation of EnergyA thin hoop of radius R rolls without slipping on an incline which makes an angle theta relative to the horizontal. If the hoop is initially at rest what is the velocity after it has rolled a distance d along the incline.
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Physics Work,Power & Energy Level: University
Find the kinetic energy of a 75-kg car that traveled 800 m in 50 seconds.( i used KE = 1/2 mxspeed to the 2 power)
Physics Work,Power & Energy Level: University
Work energy theoremHow much work is done during a 14-hour period by the trees in proud Lake Recreation area in transporting water from their root systems to their leaves (There are 3700 acres in proud Lake an average of 4840 trees per acre, average height of a tree is 44 feet and a typical tree raises 260 gallons of water during the 14-hour period.
b. If this work could be harnessed in the form of electrical energy how many 75 W light bulbs could the proud Lake trees operate during the 14-hour period?
