An electric elevator with a motor at the top has a multistrand cable weighing 4 lb/ft. When the car is at the first floor, 140 ft of cable are paid out, and effectively 0 ft are out when the car is at the top floor. How much work does the motor do just lifting the cable when it takes the car from the first floor to the top? The amount of work required is ft-lb. (Simplify your answer.)

An electric elevator with a motor at the top has a multistrand cable weighing 4 lb/ft. When the car is at the first floor, 140 ft of cable are paid out, and effectively 0 ft are out when the car is at the top floor. How much work does the motor do just lifting the cable when it takes the car from the first floor to the top? The amount of work required is ft-lb. (Simplify your answer.)

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

A heavy rope, 50 ft long, weighs 0.3 lb/ft and hangs over the edge of a building 140 ft high. (a) How much work W is done in pulling the rope to the top of the building? W = ft-lb (b) How much work W is done in pulling half the rope to the top of the building? W = ft-lb
You go for a walk one afternoon down a level street to a park where there is a hill. If the hill is 62 meters above street level and 4.6 km from home , how much work in the physics sense do you do in order to get to the top of the hill? Assume your mass is 65 kg and the acceleration of gravity is 9.8 m/s. Give your answer in joules (J).
1. The third floor of a house is 10 m above the street level. How much work is required to lift a 500 kg refrigerator to the third story level? 2. (a) How much work is done when you push a crate horizontally with 150 N across a 20 m school floor? (b) If the force of friction on the crate is a steady 50 N, what will be the KE gained by the crate? (c) How many joules of energy will be turned into heat? 3. A car moving at 60 km/h skids 20 m with locked brakes. How far will the car skid with locked brakes at 120 km/h? 4. In raising a 6000 N piano with a pulley system, the workers note that for every 3 m of rope pulled downward, the piano raises 0.3 m. What is the force required to lift the piano? 5. How many watts of power do you expend when you exert a force of 3 N that moves a book 5 m in a time interval of 2 seconds? 6. Jane holds an apple of mass m over the edge of a bridge of height h = 9m. She drops the apple and it falls to the river bellow. What will be the speed of…
The spring-flex exercise system consists of a spring with one end fixed and a handle on the other end. The idea is that you exercise your muscles by stretching the spring from its natural length, which is 38 cm. If a 170 Newton force is required to keep the spring stretched to a length of 52 cm, how much work is required to stretch it from 51 cm to 70 cm? Your answer must include the correct units. Work =
A spring has a natural length of 2 ft. A force of 20 lb stretches the spring to a length of 3 ft. Find the spring constant. Then calculate the amount of work done in stretching the spring from its natural length to 3 ft. How much work is done in stretching the spring from 4 ft to 5 ft. How far beyond the natural length will a 30 lb force stretch the spring?
Bob is pulling a box of his toys of mass 15.0 kg along a rough horizontal surface for a distance of 6.00 m. The tension force in the rope is 58.0 N and the angle is 30° with respect to the horizontal. The frictional force on the box is 18.0 N. How much work is done on the box by the tension force, in Joule? Use g = 10.0 m/s2. Your answer needs to have 3 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement.
A 50 kg woman steps onto an up-going escalator, which has an incline of 32° with respect to the horizontal and is moving at 0.5 m/s. The top of the escalator is 20 m above the ground level. Calculate how much work is done by the friction force between the woman's feet and the escalator step, as she moves from the bottom to the top of the escalator. Express your answer in joules.
Part A: If you lift a 10 kg object that weighs 10 N (22lbs.) from the floor and place it on a table 1.5 m high, how much work did you do and how much potential energy did you give the object? Assume no friction. Part B: You apply 10N force to an object for 10m, how much work did you do and how much kinetic energy did you give the object? Assume no friction.
a stack of books has a mass of 40 kg. A woman lifts the books from the floor a distance of 2 m. How much work is done? The women carries the books 15 m to her car. How much work is done. The women lowers the books 1.5 m into her car trunk. How much work is done?
The graph in the figure below shows the magnitude of the force ex- erted by a given spring as a function of the distance x the spring is stretched. How much work is needed to stretch this spring: (a) a distance of 5.0 cm, starting with it unstretched, and (b) from x - 2.0 cm to x = 7.0 cm? F (N) x (cm) 1 2 3 4 5 6 67 8 350 300 250 200 150 100 50
You and your bicycle have combined mass of 80 kg. When you reach the base of the bridge, you are traveling along the road at 5m/s. At the top of the bridge, you have climbed a vertical distance of 5.2 m and have slowed to 1.5 m/s. How much work (in J) have you done from the base to the top of the bridge? (Ignore friction.)
A force of 16 lb is required to hold a spring stretched 2 in. beyond its natural length. How much work W is done in stretching it from its natural length to 8 in. beyond its natural length? write answer as fraction