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Calculating the Stopping Distance of a Car

A car is traveling on a level road with speed v_o at the instant when the brakes lock (preventing tire rotation) so that the tires slide rather than roll. Questions: A. Use the work-energy theorem to calculate the minimum stopping distance of the car in terms of v_o, g, and the coefficient of kinetic friction, mu_k between

Life versus Intelligent Life

1. Contrast life to intelligent life? 2. Would it be possible to receive and understand a message from an extraterrestrial intelligent civilization.

work done by the piston to increase the nitrogen volume

A piston assembly changes the volume of 5 grams of nitrogen from Vi=0.03 cubic meters to Vf=0.75 cubic meters isothermally at room temperature. What is the amount of work performed by the piston? I know that nitrogen is a diatomic molecule.

motion of a crate

Find the Following: A. What is the kinetic energy of the crate as it slides on the upper surface? B. While the crate slides along the upper surface, how much gravitational potential energy does it have compared to what it would have on the lower surface? C. What is the speed of the crate when it arrives at the lower sur

Kinetic frictional force

A 1.00 x 10^2 kg crate is being pushed across a horizontal floor by a force P that makes an angle of 30.0 degrees below the horizontal. The coefficient of kinetic friction is 0.200. What should be the magnitude of P, so that the net work done by it and the kinetic frictional force is zero?

A pitcher throws a baseball with mass=.145kg straight up with initial v=25 m/s

A pitcher throws a baseball with mass=.145kg straight up with initial v=25 m/s a) How much work has gravity done on the ball when it reaches h=20m above pitcher's hand? b) Using work-energy theorem, calculate speed of baseball at h=20m above pitcher's hand c) Does the answer to part b depend on weather the ball is moving up

Final Temperature of an Insulated Tank

An insulated tank is divided into two parts by a partition. One part of the tank contains 2.5 kg of compressed liquid water at 60 degrees C and 600 kPa while the other part is evacuated. The partition is now removed, and the water expands to fill the entire tank. Determine the final temperature of the water and the volume of

Potential energy

A shot-putter puts a shot (weight=0.71 N) that leaves his hand at a distance of 1.52 m above the ground. a.) What is the work done by the gravitational force when the shot has risen to a height of 2.13 m above the ground. d.) What is the change in the gravitational potential energy of the shot.

work done by gravitational force and potential energy

A 0.60 kg ball is dropped out of a window that is 6.1 m above the ground. The ball is caught by a person whose hands are 1.5 m above the ground. a.) How much work is done on the ball by its weight? What is the gravitational potential energy of the basketball, relative to the ground, when it is b.)released and c) caught

Work Done by Forces and Work-Energy Theorem

A rescue helicopter lifts a 79 kg person straight up by means of a cable. The person has an upward acceleration of 0.70 m/s^2 and is lifted from rest through a distance of 11 m. a) What is the tension in the cable? How much work is done by b) the tension in the cable and c) the person's weight d) using the work and energy theore

Modern Physics - What is the work done on the jet by the catapult?

A fighter jet is launched from an aircraft carrier with the aid of its own engines and a steam-powered catapult. The thrust of its engines is 2.3 x 10^5 N. In being launched from rest it moves through a distance of 87 m and has a kinetic energy of 4.5 x 10^7 J at lift-off. What is the work done on the jet by the catapult?

Modern Physics - magnitude of pushing force P

A 1.00 x 10^2 kg crate is being pushed across a horizontal floor by a force P that makes an angle of 30.0 degrees below the horizontal. The coefficient of kinetic friction is .200. What should be the magnitude of P, sot that the net work done by it and the kinetic frictional force is zero?

Work Done by the Escalator and the Gravitational Force

A 75.0 kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to the floor above, a vertical height of 4.60 m. What is the work done on the man by a) the gravitational force and b) the escalator?

Barrel on inclined plane

A 40 kilogram barrel is rolled up a 10 meter ramp to a hieght of 5 meters. A) How much does the barrel weight? b) How much work was done? c) If the person exerted an effort force of 250 newtons to roll the barrel along the ramp, what is the efficiency of the ramp?

kinetic energy and distance penetrated by the pile

A pile is driven into the ground by a hammer of mass (M) 500Kg, dropped from a height of 4 meters. The mass (m) of the pile is 40Kg and the average resistance of the ground to penetration (Fr) is 45 kN. 1) Calculate the Velocity and the kinetic energy of the hammer prior to the impact with the pile. 2) Calculate the velo

Three circular motion questions

A couple of circular motion problems... I realize that this is something I could have figured out if I had more time, but I am running out of it..please help. 1. A circular disk of radius 30 cm is rotating with an angular acceleration of 1 radian/ s2. What is the tangential acceleration of a point on the rim of the disk? Wha

In moving out of a dormitory at the end of the semester

In moving out of a dormitory at the end of the semester, a student does 1.6 x 10^4 J of work. In the process, his internal energy decreases by 4.2 x 10^4 J. Determine each of the following quantities (including the algebraic sign): (a)W, (b) delta U, and (c)Q.

Work, Energy, and Friction

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a string, as shown in Figure. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is µk = 0.29. Determine the change in the kinetic energy of block A as it moves from C to D, a dist

Varying coefficient of friction

A box is sliding with a speed of 4.50 m/s on a horizontal surface, when at point P, it encounters a rough section. On the rough section, the coefficient of friction is not constant, but starts at 0.100 at P and increases linearly with distance past P, reaching a value of 0.600 at 12.5 m past point P. a) use the work-energy

Block sliding down an inclined plane

A block slides down an incline (see the fig. in the attachment). As it moves from point A to point B, which are 6.6 m apart force F acts on the block, with magnitude 3.3 N and directed down the incline. The magnitude of the frictional force acting on the block is 6.1 N. If the kinetic energy of the block increases by 28 J bet

Rotational mechanics, hydrostatics and hydrodynamics.

1 The arm in Figure P8.7 weighs 36.0 N. The force of gravity acting on the arm acts through point A. Determine the magnitudes of the tension force t in the deltoid muscle and the force s of the shoulder on the humerus (upper-arm bone) to hold the arm in the position shown. 2. One end of a uniform 6.0 m long rod of weigh

Friction Problems

See attached file for full problem description. --- 1. a) A block with a mass m is pulled along a horizontal surface for a distance +x by a constant force F at an angle theta with respect to the horizontal. The coefficient of kinetic friction between block and table is µ. Is the force exerted by friction equal to µmg?

Physics/ answers to questions

1. Which one of the following statements best explains why it is possible to define an electrostatic potential in a region of space that contains an electrostatic field? a. Work must be done to bring two positive charges closer together b. Like charges repel one another and unlike charges attract one another c. A positive c

Work-Energy Concepts

A little red wagon with a mass of 4.60 kg moves in a straight line on a frictionless horizontal surface. It has an initial speed of 10.0m/s and then is pulled 4.0 m by a force with a magnitude of 18.0 N in the direction of the initial velocity. a) Use the work-energy relation to calculate the wagon's final speed. b) Calculate

Forces in parallel

2 forces parallel to the X axis do 14.7 Joules of work on a small tray while moving it 20.7 meters in the X direction across a gym floor. One of the forces has a value of +3.89 Newton's in the X direction. What is the other force?

Heat and Thermodynamics: Work done in a cycle

Please explain problem in word or pdf format closed path with 4 processes 1st process Isochoric V= 2m^3 P-initial = 3x10^4 Pa P-final = 8x10^4 Pa 2nd process Isobaric V-initial = 2m^3 V-final= 5m^3 P = 8x10^4 3rd process Isochoric V= 5m^3 Pi =8x10^4 Pa Pf =3x10^4 Pa 4th process Isobaric Vi = 5m^3

Forces: Gravity, Friction, Constant

19. An 80N crate slides with constant speed a distance of 5.0m downward along a rough slope that makes an angle of 30 degrees with the horizontal. The work done by the force of gravity is: A. -400J B. -200J C. -69J D. 200J E. 400J 20. A man pulls a sled along a rough horizontal surface by applying a constant force F