Question

In: Physics

The Work Done in Pulling a Supertanker Solution(Mastering Physics Chapter 05: Work and Energy)

Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.30 * 106 N, one at an angle 13.0° west of north, and the other at an angle 13.0° east of north, as they pull the tanker a distance 0.650 km toward the north.

Part A

What is the total work done by the two tugboats on the supertanker?
Express your answer in joules, to three significant figures.

Part B

What is the total work done by the two tugboats on the supertanker?
Express your answer in joules, to three significant figures.

Solutions

Expert Solution

Part A Answer

Work is force times distance. The tugs are pulling at an angle to north, but each is pulling in the opposite direction (with respect to the x-direction) – so the forces cancel out in the x-direction, and the only force left is acting in the y-direction. To begin, find the y-component of the force from one of the tugs and then double it:

Fy = F*cos(θ)
Fy = 1300000 * cos(13)
Fy = 1266681 N

Now double the force, since there are two tugs. The overall force is 2533362 N. Now multiply by the distance. 0.650 km is 650m:

W = FD
W = 2533362 * 650
W = 1646685409 J

Rounded to 3 significant figures, this is 1650000000 J, or 1.65 * 10^9

1.65 * 10^9

Part B Answer

Work is force times distance. The tugs are pulling at an angle to north, but each is pulling in the opposite direction (with respect to the x-direction) – so the forces cancel out in the x-direction, and the only force left is acting in the y-direction. To begin, find the y-component of the force from one of the tugs and then double it:

Fy = F*cos(θ)
Fy = 1300000 * cos(13)
Fy = 1266681 N

Now double the force, since there are two tugs. The overall force is 2533362 N. Now multiply by the distance. 0.650 km is 650m:

W = FD
W = 2533362 * 650
W = 1646685409 J

Rounded to 3 significant figures, this is 1650000000 J, or 1.65 * 10^9 J

1.65 * 10^9 J

Related Solutions

Where’s the Energy Solution(Mastering Physics Chapter 05: Work and Energy)
In this problem, we will consider the following situation as depicted in the diagram: A block of mass m slides at a speed v along a horizontal, smooth table. It next slides down a smooth ramp, descending a height h, and then slides along a horizontal rough floor, stopping eventually. Assume that the block slides slowly enough so that it does not lose contact with the supporting surfaces (table, ramp, or floor). You will analyze the motion of the block...
Sliding in Socks Solution(Mastering Physics Chapter 05: Work and Energy)
Suppose that the coefficient of friction between your feet and the floor, while wearing socks, is 0.250. Knowing this, you decide to get a running start and then slide across the floor. Part A If your speed is 3.00 m/s when you start to slide, what distance will you slide before stopping?Express your answer in meters. Part B Now, suppose that your young cousin sees you sliding and takes off her shoes so that she can slide as well (assume...
Bungee Jumping Solution(Mastering Physics Chapter 05: Work and Energy)
Kate, a bungee jumper, wants to jump off the edge of a bridge that spans a river below. Kate has a mass m, and the surface of the bridge is a height h above the water. The bungee cord, which has length L when unstretched, will first straighten and then stretch as Kate falls. Assume the following: The bungee cord behaves as an ideal spring once it begins to stretch, with spring constant k. Kate doesn’t actually jump but simply...
Springs in Two Dimensions Solution(Mastering Physics Chapter 05: Work and Energy)
The ends of two identical springs are connected. Their unstretched lengths l are negligibly small and each has spring constant k. After being connected, each spring is stretched an amount L and their free ends are anchored at y = 0 and x = ±L as shown (Figure 1) . The point where the springs are connected to each other is now moved from the origin to a position (x, y). Assume that (x, y) lies in the first quadrant....
The Fuel of Migrating Birds Solution(Mastering Physics Chapter 05: Work and Energy)
Small birds can migrate over long distances without feeding, storing energy mostly as fat rather than carbohydrate. Fat is a good form of energy storage because it provides the most energy per unit mass: 1 gram of fat provides about 9.4 (food) Calories, compared to 4.2 (food) Calories per 1 gram of carbohydrate. Remember that Calories associated with food, which are always capitalized, are not exactly the same as calories used in physics or chemistry, even though they have the...
Energy Required to Lift a Heavy Box Solution(Mastering Physics Chapter 05: Work and Energy)
As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. There is no one around to help, so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. You pull up on the rope to lift the box. Use g for the magnitude of the acceleration due to gravity and neglect friction forces. Part...
Energy Required to Lift a Heavy Box Solution(Mastering Physics Chapter 05: Work and Energy)
Two children are trying to shoot a marble of mass m into a small box using a spring-loaded gun that is fixed on a table and shoots horizontally from the edge of the table. The edge of the table is a height H above the top of the box (the height of which is negligibly small), and the center of the box is a distance d from the edge of the table. The spring has a spring constant k. The...
Problem 6.73(Mastering Physics Chapter 05: Work and Energy)
In a certain library the first shelf is 15.0 cm off the ground, and the remaining four shelves are each spaced 31.0 cm above the previous one. Part A If the average book has a mass of 1.4 kg with a height of 22 cm, and an average shelf holds 29 books, how much work is required to fill all the shelves, assuming the books are all laying flat on the floor to start?
Problem 6.37(Mastering Physics Chapter 05: Work and Energy)
A 71 kg trampoline artist jumps vertically upward from the top of a platform with a speed of 4.7 m/s. Part A  What is his speed as he lands on the trampoline, 2.2 m below his jump off point? Part B If the trampoline behaves like a spring with spring stiffness constant 7.1 * 10^4 N/m , how far does he depress it? Any depression of the trampoline from equilibrium is to be taken as a negative distance.
Shooting a Block up an Incline Solution(Mastering Physics Chapter 05: Work and Energy)
A block of mass m is placed in a smooth-bored spring gun at the bottom of the incline so that it compresses the spring by an amount xc. The spring has spring constant k. The incline makes an angle θ with the horizontal and the coefficient of kinetic friction between the block and the incline is μ. The block is released, exits the muzzle of the gun, and slides up an incline a total distance L. Part A Find L,...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT