# BrookeNeed

Most popular questions and responses by BrookeNeed
1. ## physics

A water-skier is being pulled by a tow rope attached to a boat. As the driver pushes the throttle forward, the skier accelerates. A 71.6-kg water-skier has an initial speed of 5.8 m/s. Later, the speed increases to 11.8 m/s. Determine the work done by the

2. ## physics

A fisherman is fishing from a bridge and is using a "51.0-N test line." In other words, the line will sustain a maximum force of 51.0 N without breaking. What is the weight of the heaviest fish that can be pulled up vertically, when the line is reeled in

3. ## physics

Starting from rest, a 93-kg firefighter slides down a fire pole. The average frictional force everted on him by the pole has a magnitude of 710 N, and his speed at the bottom of the pole is 3.2 m/s. How far did he slide down the pole? What equation do you

4. ## Physics

You are moving into an apartment and take the elevator to the 6th floor. Suppose your weight is 770 N and that of your belongings is 1040 N. Determine the work done by the elevator in lifting you and your belongings up to the 6th floor (15.2 m) at a

5. ## physics

"Rocket Man" has a propulsion unit strapped to his back. He starts from rest on the ground, fires the unit, and accelerates straight upward. At a height of 16 m, his speed is 5.5 m/s. His mass, including the propulsion unit, has the approximately constant

6. ## physics

A 40.2-kg skater is standing at rest in front of a wall. By pushing against the wall she propels herself backward with a velocity of -1.84 m/s. Her hands are in contact with the wall for 1.17 s. Ignore friction and wind resistance. Find the average force

7. ## Physics

A "swing" ride at a carnival consists of chairs that are swung in a circle by 17.9 m cables attached to a vertical rotating pole, as the drawing shows. Suppose the total mass of a chair and its occupant is 193 kg. (a) Determine the tension in the cable

8. ## Physics

In a fast-pitch softball game the pitcher is impressive to watch, as she delivers a pitch by rapidly whirling her arm around so that the ball in her hand moves in a circle. In one instance, the radius of the circle is 0.622 m. At one point on this circle,

9. ## physics

The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force that the sun exerts on the moon is perpendicular to the force that the earth exerts on the moon. The masses are: mass of sun=1.99 × 1030 kg, mass of

10. ## Physics

A stuntman is being pulled along a rough road at a constant velocity by a cable attached to a moving truck. The cable is parallel to the ground. The mass of the stuntman is 109 kg, and the coefficient of kinetic friction between the road and him is 0.621.

11. ## Physics

A 4.05 x 10-2-kg block is resting on a horizontal frictionless surface and is attached to a horizontal spring whose spring constant is 121 N/m. The block is shoved parallel to the spring axis and is given an initial speed of 8.65 m/s, while the spring is

12. ## Physics

Starting from rest, a 1.7x10-4 kg flea springs straight upward. While the flea is pushing off from the ground, the ground exerts an average upward force of 0.45 N on it. This force does 1.9x10-4 J of work on the flea. (a) What is the flea's speed when it

13. ## Physics

A person whose weight is W = 658 N is doing push-ups. From his feet to his center of gravity he is 0.840m and from the center of gravity to his hands is 0.410m. Find the normal force exerted by the floor on (a) each hand and (b) each foot, assuming that

14. ## Physics

A woman stands on a scale in a moving elevator. Her mass is 65.0 kg, and the combined mass of the elevator and scale is an additional 757 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force

15. ## Physics

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used

16. ## physics

A car travels at a constant speed around a circular track whose radius is 2.87 km. The car goes once around the track in 332 s. What is the magnitude of the centripetal acceleration of the car?

17. ## physics

The concepts in this problem are similar to those in Multiple-Concept Example 4, except that the force doing the work in this problem is the tension in the cable. A rescue helicopter lifts a 89.2-kg person straight up by means of a cable. The person has an

18. ## physics

A woman stands on a scale in a moving elevator. Her mass is 65.0 kg, and the combined mass of the elevator and scale is an additional 757 kg. Starting from rest, the elevator accelerates upward. During the acceleration, the hoisting cable applies a force

19. ## Physics

After skiding down a snow-covered hill on an inner tube, Ashley is coasting across a level snowfield at a constant velocity of +3.4 m/s. Miranda runs after her at a velocity of +4.0 m/s and hops on the inner tube. How fast do the two of them slide across

20. ## Physics

A 96.4-kg person stands on a scale in an elevator. What is the apparent weight when the elevator is (a) accelerating upward with an acceleration of 1.86 m/s2, (b) moving upward at a constant speed

21. ## phy

A 221-kg log is pulled up a ramp by means of a rope that is parallel to the surface of the ramp. The ramp is inclined at 27.7° with respect to the horizontal. The coefficient of kinetic friction between the log and the ramp is 0.811, and the log has an

22. ## Physics

A cup of coffee is on a table in an airplane flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.410 . Suddenly, the plane accelerates forward, its altitude remaining constant. What

23. ## physics

A 50.4-g golf ball is driven from the tee with an initial speed of 45.7 m/s and rises to a height of 26.9 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 7.80 m below its

24. ## Physics

A person in a kayak starts paddling, and it accelerates from 0 to 0.568 m/s in a distance of 0.389 m. If the combined mass of the person and the kayak is 79.5 kg, what is the magnitude of the net force acting on the kayak?

25. ## Physics

A cylindrically shaped piece of collagen (a substance found in the body in connective tissue) is being stretched by a force that increases from 0 to 0.0436 N. The length and radius of the collagen are, respectively, 2.90 cm and 0.0815 cm, and Young's

26. ## physics

A two-stage rocket moves in space at a constant velocity of +4890 m/s. The two stages are then separated by a small explosive charge placed between them. Immediately after the explosion the velocity of the 1380-kg upper stage is +5660 m/s. What is the

27. ## Physics

A 221-kg log is pulled up a ramp by means of a rope that is parallel to the surface of the ramp. The ramp is inclined at 27.7° with respect to the horizontal. The coefficient of kinetic friction between the log and the ramp is 0.811, and the log has an

28. ## Physics

A 8.06-kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.402. Determine the kinetic frictional force that acts on the box when the elevator is (a) accelerating upward with