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Using the Work-Energy Theorem

Pushing a Cat. Your cat "Ms." (mass 7.00 kg) is trying to make it to the top of a frictionless ramp 2.00 m long and inclined upward at 30.0 degree above the horizontal. Since the poor cat can't get any traction on the ramp, you push her up the entire length of the ramp by exerting a constant 100-N force parallel to the ramp.

Calculating Work and Kinetic Energy

(See attached file for full problem description) --- Consider the system shown in the figure. The rope and pulley have negligible mass, and the pulley is frictionless. The coefficient of kinetic friction between the 8.00-kg block and the tabletop is . The blocks are released from rest. Use energy methods to calcula

Work required to move electric charges to infinity

A rectangular box has three charges at the corners with the length of the box being x = 0.55 m and height y = 0.36 m. How much work must be done to move the three charges; -3.3 µC, -6.1 µC, and +2.7 µC infinitely far from one another?

What is the velocity of the proton just before it hits the negative plate?

Please see the attached file for full problem description. 5. Two metal plates are held at a potential difference of 40 volts, in a vacuum. A proton is released near the positive plate, and moves toward the negative plate under the influence of the electric field. A proton's mass is 1.67 * 10^-27 kg. (A) Just before the pr

Electric Potential Energy of a Solid Charged Sphere

Calculate the electric potential energy of a solid sphere of uniform charge density rho; total charge Q and radius a using dU = dq(Vf - Vi). See attached file for full problem description with proper symbols.

Basic Physic Questions

Question 1: A 3.0-g bullet traveling at 350 m/s hits a tree and slows down uniformly to a stop while penetrating a distance of 12 cm into the tree's trunk. What was the force exerted on the bullet in bringing it to rest? Question 2: A big car of mass 2m travels at speed v, and a small car of mass m travels with a speed 2v. Bo

Calculating car engine efficiency in gasoline burn

The burning of gasoline in a car releases about 2.85à?104 kcal per gallon. If a car averages 42.9 km/gallon when driving 86.2 km/hr, which requires 24.9 hp, what is the efficiency (in percent) of the engine under those conditions?

Work per second by engine

A 4-cylinder gasoline engine has an efficiency of 0.230 and delivers 205 J of work per cycle per cylinder. When the engine fires at 23.3 cycles per second, what is the work done per second?

Kinetic Energy and Radiation with Electrons

Radiation of a certain wavelength causes electrons with a maximum kinetic energy of 0.62 eV to be ejected from a metal whose work function is 2.65 eV. What will be the maximum kinetic energy (in eV) with which this same radiation ejects electrons from another metal whose work function is 2.01 eV? Units are in eV.

Energy Loss/Speed

Take g= 9.8ms(-2) Please answer all questions with full explanations thank you A cyclist starting from rest freewheels for 200m down a slope of 1 in 10 (sin0 = 0.1) If the mass of the cycle and rider is 75kg: 1) What is the loss of potential energy of the cycle+rider? 2) If the speed of the cycle at the bottom of the h

Forces, Fields and Energy - Gravitational Fields

The distance between the centers of the Earth and the moon is 3.8 x 10^8 m. Assume that the moon moves in a circular orbit about the center of the Earth. Estimate the period of the orbit to the nearest day. *Mass of earth = 6.0 x 10^24 kg *1 day = 8.6 x 10^4 seconds *Distance between the centers of Earth and Moon = 3.8 x 10^8

A pump submerged at the bottom of a well that is 35m deep

(See attached file for full problem description with diagram) --- 6. A pump, submerged at the bottom of a well that is 35m deep, is used to pump water uphill to house that is 50m above the top of the well, as shown above. The density of water is 1,000 kg/m3. All pressures are gauge pressures. Neglect the effects of friction,

Tennis player receives shot with the ball and returns the shot

A tennis player receives a shot with the ball (0.0600 kg) traveling horizontally at 50.0 m/s and returns the shot with the ball traveling horizontally at 36.0 m/s in the opposite direction. (Assume the initial direction of the ball is in the -x direction.) (a) What is the impulse delivered to the ball by the racquet? i N ·

Ball slided down incline and encounters rough surface

1.) A 1-kg ball starting at h = 7.2 meters slides down a smooth surface where it encounters a rough surface and is brought to rest at B, a distance 26.6 meters away. To the nearest joule what is the work done by friction? 2.) To two decimal places, what is the coefficient of friction? See attached file for full problem des

Work performed by a skier: Example problem

A skier of mass 69.3 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him a distance of 59.0 m up a 30.4° slope (assumed frictionless) at a constant speed of 1.97 m/s? (b) A motor of what power is required to perform this task?

Physics Review

Mark the following statements true or false. If you mark it false, tell why it is false and how it could be changed to make it true. 1. If a force F acts on a particle of mass m which is moving at a speed v, we define the work done to be the change in the quantity 1/2mv^2. 2. Work is necessarily a positive quantity. 3.

Independent Wing Span Size Analysis

Question78: All birds, independent of their size, must maintain a power output of 10 to 25 watts per kilogram of body mass in order to fly by flapping their wings. (a) The Andean giant hummingbird (Pantagona Gigas) has a mass of 70g and flaps its wings ten times per second while hovering. Estimate the amount of work done

Energy is conventionally measured in Calories

Energy is conventionally measured in Calories as well as in joules. One Calorie in nutrition is one kilocalorie, defined as 1 kcal = 4186 J. Metabolizing one gram of fat can release 9.00 kcal. A student decides to try to lose weight by exercising. She plans to run up and down the stairs in a football stadium as fast as she can a

Water Jumped from Well

Having much difficulty with this word problem: A water well has an 8-inch diameter and is 175 feet deep. Assume that water enters the well at a rate of 4 gallons per minute and the pump works at a rate of 12 gallons per minute. If the water is 25 feet from the top of the well, determine the amount of work done in pumping it

Friction, Motion and Work

A 920 N crate rests on the floor. How much work is required to move it at constant speed 5.40 m along the floor against a friction force of 176 N?

Physics Questions

1. There is an analogy between rotational and translational physical quantities. Identify the rotational term analogous to each of the following linear quantities: acceleration, force, mass, work, translational kinetic energy, linear momentum, impulse. (Example: impulse F Delta-t corresponds to angular impulse, tau Delta-t . (Gr

Physics Questions

1. (a) What is the momentum of a 1.20 x 10^4 kg garbage truck moving at 30.0 m/s? (b) At what speed would an 8.00 kg trash can have the same momentum? 2. One hazard of space travel is debris left by previous missions. There are several thousand masses large enough to detect by radar orbiting the earth, but there are far grea

Solving for Force

Here is the problem: I don't understand what x and y in the force is for. Please show full solution A force F = (4x i + 4y j) N acts on an object as it moves in the x direction from the origin to x = 4.94 m. Find the work W = F · dr done on the object by the force.

Frequency, Amplitude, Mass

A spring of force constant 4.0 N/m oscillates with a period of 1.0 sec. with a particular mass m attached. A total energy of 0.130 J is put into the spring-mass system. What is the frequency of the motion? Find the amplitude of the motion. Find the value of the mass, m. What is the speed of the mass when its displacement is 15.0

Need some help on a take home assignment to

1, Three identical balls are thrown from the top of a building, all with the same initial speed. Ball 1 is thrown horizontally, ball 2 is thrown at some angle above the horizontal, and ball 3 is thrown at some below the horizontal. Rank the speed of the balls as they reach the ground from fastest to slowest. A,1-2-3 B,2-1-3