14. A cable is 12 m long and has a density of 5 kg/m. If the cable is hanging with a 20 kg bucket attached, how much work is done winding it up? Sketch what is happening. 14. A cable is 12 m...
9. a. A spring has constant k-5lb./in. Its natural length is 12 inches. What is the work required to compress it to 9 inches? b. A 100 ft. cable weighs 40 lbs. Find the work done in winding the cable onto a winch, if the cable is hanging vertically c. An unknown positive charge q is placed at the origin. The force F (in Newtons) with which this charge repels a unit positive charge is given by F-kq/r, where k...
Airflow lifts a 3.6 kg bird 50 m up. a) How much work was done by the flow? b) How much did its gravitational potential energy increase? A bird flies at a speed of 2.3 m/s if it has 14 J of kinetic energy. What is its mass?
An 8.0-kg bucket is attached to a long string forming a pendulum. It is released from rest at a height of 1.2 m above the equilibrium position of the pendulum. It swings down and, as it reaches the equilibrium position, it has a speed of 4.0 m/s. Do not presume that air resistance can be neglected. a. [1] What does “equilibrium” mean in physics? Do not justify. b. [5] Determine i. the work done by tension ii. and the work...
How much work is done on a 5 kg block if it is to be moved on a ramp 30° above the horizontal and height of 1 meter? What are the values of work done by each force?
A 1300 kg wrecking ball hangs from a 12-m-long cable. The ball is pulled back until the cable makes an angle of 15.0 ∘ with the vertical. By how much has the gravitational potential energy of the ball changed?
1- How much work is done by the horizontal force Fp = 150N on the 18-kg block when the force pushes the block 5.0 m up along the 32° frictionless incline? (b) How much work is done by the gravitational force on the block during this displacement? (c) How much work is done by the normal force? (d) What is the speed of the block (assume that it is zero initially) after this displacement? [Hint: Work-energy involves net work done.]...
A 60-m-long chain hangs vertically from a cylinder attached to a winch. Assume there is no friction in the system and that the chain has a density of 9 kg/m. Use 9.8 m/s for the acceleration due to gravity. a. How much work is required to wind the entire chain onto the cylinder using the winch? b. How much work is required to wind the chain onto the cylinder if a 50-kg block is attached to the end of the...
7. (20 pts) A force of 50 N is used to move a 5 kg box 30 m across a level floor. a. How much work was done on the box? b. If the movement takes 10 seconds, what is the average velocity of the box during the move? c. What is the average kinetic energy of the box during the move? d. What is the change in potential energy as a result of this move?
A 40-kg pack is carried up a 2500-m-high mountain in 10.0 h. How much work is done?
A 4-m long, 150-kg steel beam is attached to a wall with one end connected to a hinge that allows the beam to rotate up and down. The other end of the beam is held in a horizontal position with a cable that makes a 27° angle with the beam and is attached to the wall (see (Figure 1)). What is the tension force that keeps this beam in static equilibrium?