Physics Work,Power & Energy Level: High School
Power
A 550 kg elevator starts from rest . It moves upward for 2.00 s with constant acceleration until it reaches its cruising speed , 1.75 m/s .a) What is the average power of the elevator motor during this period ?
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
An object of mass m starts from rest and slides a distance d down a frictionless incline of angle theta . While sliding ,it contacts an unstressed spring of negligible mass as shown in the figure at “click here” . The object slides an additional distance x as it is brought momentarily to rest by compression of the spring . (Use theta for theta , g for acceleration due to gravity , and m , k and x as necessary.)
Physics Work,Power & Energy Level: High School
Conservation of Energy
A particle of mass m = 6.20 kg is released from point A and slides on the frictionless track down in the figure at “click here”. (ha = 7.70 m)a) Determine the particle’s speed at point B and C .
b) Determine the network done by the gravitational force in moving the particle from A to C.
Physics Work,Power & Energy Level: High School
Conservation of Energy
A vertical spring with a spring constant of 530 N/m is mounted on the floor . From directly above the spring ,which is unstrained a 0.30 kg block is dropped from rest . It collies with and sticks to the spring ,which is compressed by 2.9 cm in bringing the block to a momentary halt . Assuming air resistance is negligible ,from what height (in cm) above the compressed spring was the block dropped ?
Physics Work,Power & Energy Level: High School
Conservation of Energy
In preparation for shooting a ball in a pinball machine , a spring (k = 680 N/m) is compressed by 0.0685 m relative to its unstrained length . The ball (m = 0.0600 kg) is at rest against the spring at point A . When the spring is released , the ball slides (without rolling to point B , which is 0.300 m higher than point A . How fast is the ball moving at B ?
Physics Work,Power & Energy Level: High School
Inelastic Collision
A box of mass 4.1 kg slides on a frictionless surface at a speed of 18.2 m/s , heading towards another box of unknown mass which is at rest . The first box collides identically with the second box and sticks to it , and the two boxes move off together at a speed of 8.1 m/s . What is the mass (in kg) of the second box ?a) 4.5
b) 5.1
c) 5.6
d) 6.5
e) 7.4
Physics Work,Power & Energy Level: High School
A skier is initially at rest at the top of a tall sky slope with a total energy of 100 J. Exactly halfway down the hill , the skiers kinetic energy is measured to be 40 J . How much energy did the skier lose due to friction in the ski slope ?a) 20 J
b) 80 J
c) 50 J
d) 10 J
e) 60 J
Physics Work,Power & Energy Level: High School
Friction
A roller coaster has an initial speed of 3 m/s at the top of the first hill . which is 44 m above the ground . Neglecting friction , what will be the speed (in m/s ) of the roller coaster at the top of the third hill , which is 24 m above the ground ?a) 17.1
b) 20.1
c) 23.5
d) 27.5
e) 32.1
Physics Work,Power & Energy Level: High School
Friction
You are sitting on your sled at the top of a steep hill . The hill is icy (frictionless) . At the bottom of the hill , the ground is flat and still icy (frictionless) . except for one patch of rough gravel (coefficient of kinetic friction = 0.17 ) that is 5.5 m long . If the vertical height of the hill is 22.9 m . What would be your speed in (m/s) after traveling the gravel patch ?a) 8.08
b) 11.7
c) 15.6
d) 20.7
e) 27.6
Physics Work,Power & Energy Level: High School
Conservation of Energy
How fast must a 10.5 g bullet be traveled when it strikes a ballistic pendulum that consists of a block of wood of mass 3.0 kg that is suspended by a cord ? The bullet gets embedded in the block . The block rises by 0.22 m after the impact .595 m/s
2.67 m/s
595 m/s
143 m/s
Physics Work,Power & Energy Level: High School
A 70 kg cart is pushed for 50 m with a constant velocity upon a 45 degree frictionless incline . Find the work done on the cart ( Assume g = 10 m/s2)2.5 x 105 J
2.5 x 106 J
2.5 x 104 J
4.0 x 104 J
Physics Work,Power & Energy Level: High School
A 100 kg object is pulled vertically upward 5 m by a rope with an acceleration of 1 m/s2 , Find the work done by the tension force in the rope . (Assume g = 10 m/s^2 )-5500 J
-5000 J
5500 J
5000 J
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 0.4 kg ball is thrown vertically upward with a speed of 30 m/s . The ball reaches a height of 40 m . Assuming g = 10 m/s^2 , the energy dissipated due to air friction is ?20 J
160 J
340 J
180 J
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
A compressed spring that obeys Hooke’s law has a potential energy of 18 J . If the spring constant of the spring is 4 N/cm . find the distance by which the spring is compressed .0.3 m
0.3 cm
4.5 cm
3 m
Physics Work,Power & Energy Level: High School
In a kid’s dart gun , a spring is compressed and held in place by a latch until the gun is “fired” and the dart launched upward by the spring . Suppose the spring (ideal of course ) is compressed 0.0500 m when the gun is loaded , and the spring constant is 600.0 N/m .a) If the dart gun is aimed straight up , how will it shoot a 0.0150 kg dart ?
b) Suppose the dart gun spring also gave a spin to the dart . Would a spring dart go as a non-spinning dart ? Why or why not ?
