Physics Work,Power & Energy Level: High School
A block is pushed across a rough horizontal surface from point A to point B by a force P = 5.4 N as shown in the figure at “click here” . The magnitude of the frictional force action on the block between A and B is 1.2 N and points A and B are 0.5 m apart . If the kinetic energies of the block at A and B are 4.0 ad 5.6 J respectively , how much work is done on the block by the force P between A and B ?
Physics Work,Power & Energy Level: High School
An object moving along x axis is acted upon by a force F (x) that varies with position as shown in the figure at “click here“ How much work is done by this force as the object moves from 2m to 8m ?
Physics Work,Power & Energy Level: High School
A skier weighing 0.70 kN goes over a frictionless circular hill as shown in the figure at “click here” . If the skier’s speed at point A is 9.2 m/sec . what is the speed at the top of the hill . Identity what your system is in your solution .
Physics Work,Power & Energy Level: High School
A spring with spring constant 600 N/m is placed in a vertical position with its lower end supported by a horizontal surface . A 2.0 kg block that is initially 0.40 m above the upper end of the spring is dropped from rest onto the spring . What is the kinetic energy of the block at the instant it has fallen 0.50 m (compressing the spring 0.10 ) ?
Physics Work,Power & Energy Level: High School
(a) Explain what is meant by positive work and negative work done on an object in terms of the total mechanical energy of that object .(b) Does the work on an object by friction ever reduce the total internal energy of a system ? Explain .
Physics Work,Power & Energy Level: High School
A 2.0 kg block is projected down a plane that makes an angle of 20 degrees to the horizontal with an initial kinetic energy of 2.0 J .If the coefficient of kinetic friction between the block and the plane is 0.40 , how far will the block slide down the plane before coming to rest ? Applied the Work-Energy Theorem to solve . Consider the system to be the block , the plane , and Earth .
Physics Work,Power & Energy Level: High School
A surprising demonstration involves dropping an egg from a third floor window to land on a foam rubber pad 5 cm thick without breaking . If the 56 g egg falls 12 m and the foam pad stops the egg in 6.25 milliseconds . by how much work does the work exert on the egg in stopping it ? In your energy consideration consider the system to be the egg and the earth .
Physics Work,Power & Energy Level: High School
A 1.2 kg mass is projected down a rough circular track (radius = 2.0 m) . The speed of the mass at point A is 3.2 m/s , and at point B it is 6.0 m/s , How much work is done on the mass between A and B by the force of friction ? The angle between A and B is 90 degrees .
Physics Work,Power & Energy Level: High School
A skier weighing 0.70 kN goes over a frictionless circular hill , (r = 10.0 m) . If the skier’s speed at point A is 9.2 m/s , What is the speed at the top of the hill (point B) ? The angle between A and B is 45 degrees .
Physics Work,Power & Energy Level: High School
A 2.0 kg block situated on a frictionless incline is connected to a light sprig (k=100 N/m) . The block is released from rest when the spring is unstreched . The pulley is frictionless and has negligible mass . What is the speed of the block when it has moved 0.20 m down the plane ?
Physics Work,Power & Energy Level: High School
A 4.0 kg block is lowered down a 37 degree incline a distance of 5.0 m from point A to point B . A horizontal force (F = 10 N) is applied to the block between A and B . The kinetic energy of the block at A is 10 J and at B it is 20 J . How much work is done on the block by the force of friction between A and B ?
Physics Work,Power & Energy Level: High School
A 2.0 kg particle has an initial velocity of (5i – 4j )m/s . Some time later , its velocity is ( 7i + 3j) m/s . What work was done by the resultant force during this time interval . Assume no energy is lost in the process ?
Physics Work,Power & Energy Level: High School
Discuss briefly showing truth or falsity .(a) A cannon ball has twice as much energy if it is given twice as much velocity .
(b) A freely falling body falls 5 times as far during the third second as it falls during the first second ?
(c) A long to line is more effective than a short one for hauliling a canal boat ?
(d) A ski jumper has a mass of 80 kg . Would the skier s greater mass create a advantage , dis-advantage or make no difference ? Explain clearly .
Physics Work,Power & Energy Level: High School
A mass of 5.0 kg is hung from the end of a vertical spring , As a result of the addition of this mass the spring is stretched a distance of 125 cm . The spring is then lifted up until the spring is unstreched . The mass is then released and is allowed to fall until at some point it stops .(a) How far will the mass have fallen when it stops at the lowest point ?
(b) What will be the gravitational potential energy of this system when the mass is at the highest point ?
(c) What will be the elastic potential energy stored in the spring when the mass is at the lowest point ?
(d) What will be the kinetic energy at equilibrium ?
Physics Work,Power & Energy Level: High School
The ski jumper of mass 40.0 kg pushes off the top of a hill with a initial speed of 4.0 m/s . (slope angle 37 degrees and Uk = 0.10 )(a) How fast will she be moving after dropping 10.0 m in elevation ?
(b) How far will the skier then slide horizontally at the bottom of the hill ?
