Physics Work,Power & Energy Level: High School
Two identical gliders on an air track are held together by a piece of string , compressing the spring between the gliders. While they are moving to the right at a common speed of 0.50 m/s , someone holds a match under the string and burns it , letting the spring force of the gliders slide apart. One glider is then observed to be moving to the right at 1.30 m/s .(a) What velocity does the other glider have ?
(b) If the total kinetic energy of the two gliders after the collision greater than , less then or equal to the total kinetic energy before the collision ? If greater , where did the extra energy come from ? If less , where did the “lost energy” go ?
Physics Work,Power & Energy Level: High School
A sports car traveling along a straight line increases its speed from 20 mi/h to 60 mi/h .(a) What is the ratio of the final to initial magnitude of its momentum ?
(b) What is the ratio of the final to initial kinetic energy ?
Physics Work,Power & Energy Level: High School
Collision
The balls have the same mass . The blue ball is initially displaced by an angle q = 18.0 , and released from rest . The length of the cord is .86 m. Find the maximum height of the red ball . (measure from its lowest point )(a) If the collision is elastic
(b) If the balls stick together after the collision
Physics Work,Power & Energy Level: High School
Collision
In the figure the mass m1 starts from rest, and slides down the frictionless incline the mass m1 starts from rest , and slides down the frictionless inline . It collides with block m2 ( which is also at rest ) , and they move of together. If m1 = 5.3 kg , m2 =13.0 kg , and h = 2.6 m , Find(a) The speed of the m1 just before the collision .
(b) The speed of both blocks just after the collision
(c) The change in kinetic energy during the collision for the system as a whole . Attach signs : + if KE is gained , - KE is lost .
Physics Work,Power & Energy Level: High School
The green mass starts from rest at the top of the hill . It collides with the red mass , which is initially at rest , at the bottom . (The size of the two masses is the same ) . The two objects move together until they are stopped by frictional forces . There is no frictional force acting on the green object before the collision . The coefficient of friction between both masses and the flat surface is 0.41 , and the stopping distance is 4.4 m .Give an analysis expression for the work done by friction .
Physics Work,Power & Energy Level: High School
The force shown in the figure at “click here” acts on an object that moves along the x axis .(a) How much work is done by the force as the object moves from x = 0 to x = 1.6 m ?
(b) How much work is done by the force as the object moves from x = 0.7 m to x = 4.0 m ?
(c) How much work is done by the force as the object moves from x = 2.0 m to x = 3.9 m ?
Physics Work,Power & Energy Level: High School
Nuclear reactor continuously generates 150 MW of power through the fissioning of uranium . Suppose that each fission releases 190 MeV. If one mole of U (6.023 * 10 power 23) has a mass of 0.235 kg . What mass of U has undergone fissionin a 4.0 day period ?
Physics Work,Power & Energy Level: High School
A flight attendant pulls her 70.0 N flight bag a distance of 257 m along a level airport floor at a constant speed . The force she exerts is 36.0 N at an angle of 52.0 degree above the horizontal .(a) Find the work she does on the flight bag .
(b) Find the work done by the force of friction on the flight bag .
(c) Find the coefficient of kinetic friction between the flight bag and the floor
Physics Work,Power & Energy Level: High School
A skier of mass 65.0 kg is pulled up a slope by a motor-driven cable . How much work is required to pull the skier 62.0 m up a 35 degree slope (assumed to be frictionless ) at a constant speed of 2.0 m/ s ?
Physics Work,Power & Energy Level: High School
A 0.55 kg rubber ball has a speed of 2.0 m/s at point A and kinetic energy of 9.0 J at point B .(a) Determine the ball’s speed at B .
(b) Determine the total work done on the ball as it moves from A to B ?
Physics Work,Power & Energy Level: High School
Water flows over a section of Niagara Falls at the rate of 1.2 x 10^6 kg /s and falls 47.0 m. How much power is generated by falling water ?
Physics Work,Power & Energy Level: High School
A 88.96 N collar slides without friction along a vertical rod as shown in the figure at “click here” . A spring (k = 525.4 N/m) attached to the collar is not stretched when it is located at position A (the distance between the posts is 10.16 cm ) . The collar is released from rest at position A which is 20.40 m above the floor , Determine the collar’s speed after it has moved 15.24 cm down the rod to position B.
Physics Work,Power & Energy Level: High School
A 200 kg roller coaster starts from rest at point A and begins to coast down the track . the track distance from point A to point B is 50 m and the track distance from point B to point C is 30 m . There is a constant retarding friction force of 15N along the track distance from point A to point C. Determine the speed V of the car at point B and C .
Physics Work,Power & Energy Level: High School
A 60 kg sled slides o the bottom of a 25 degree slope of length 20 m . A 100 N friction force acts on the entire distance . What is the total energy at the top and the bottom . What is the velocity of the sled at the bottom ?
Physics Work,Power & Energy Level: High School
A 20 kg sled is pushed up a 34 degree slope to a vertical height of 140 m. A constant friction force of 50 N acts for the entire distance . Calculate work and change in potential energy .