Katie pushes on a 10 kg box with 70 N of force, but the box only accelerates by 3 m/s2. How much friction is there?
Question 2
If Max does 500 J of work spinning a 10% efficient generator, how much electrical energy will he produce?
Question 3
A 10 kg go-kart driven by a 30 kg boy starts from rest and rolls down a hill of height 10 m.
What is the predicted speed of the boy and go-kart at the bottom of the hill?
Question 4
A man applies 500 N of horizontal force to push a 100 kg wooden crate 20 m across a floor.
What is the work that the man performs upon the crate over the 20 m distance? (Answer in kJ)
Question 5
A man applies 500 N of horizontal force to push a 100 kg wooden crate 20 m across a floor.
When sliding, the crate experiences a friction force of 200 N in the direction opposite its motion. What is the work that the friction does upon the crate over the 20 m distance?
Question 6
A man applies 500 N of horizontal force to push a 100 kg wooden crate 20 m across a floor.
What is the net work done on the crate?
Question 7
A man applies 500 N of horizontal force to push a 100 kg wooden crate 20 m across a floor.
What is the change in the crate’s kinetic energy? (Answer in kJ)
Question 8
A man applies 500 N of horizontal force to push a 100 kg wooden crate 20 m across a floor.
Calculate the efficiency with which the man’s work is turned into the crate’s kinetic energy. (answer in decimal form)
Question 9
A moving hockey stick hits a stationary 160 g hockey puck (m = 0.16 kg) and applies a horizontal force F to the puck. The two objects remain in contact for the first 0.25 m (25 cm) of the puck’s motion. The puck then slides away at a speed v of 20 m/s. What force F is delivered to the puck?
Question 10
A weightlifter grabs a 50 kg barbell resting on the floor, raises it 2 m, then holds it in place.
What is the barbell’s kinetic energy before being lifted?
Question 11
A weightlifter grabs a 50 kg barbell resting on the floor, raises it 2 m, then holds it in place.
What is the barbell’s kinetic energy when the lift is complete?
Question 12
A weightlifter grabs a 50 kg barbell resting on the floor, raises it 2 m, then holds it in place.
What is the barbell’s change in kinetic energy?
Question 13
A weightlifter grabs a 50 kg barbell resting on the floor, raises it 2 m, then holds it in place.
What is the net work done on the barbell?
Question 14
A weightlifter grabs a 50 kg barbell resting on the floor, raises it 2 m, then holds it in place.
How much work does the weightlifter perform on the barbell?
Question 15
Consider a rubber ball which has an efficiency in one bounce of 79%. (That means 79% of the kinetic energy before the bounce remains kinetic energy after the bounce, while the rest of the energy is converted to thermal energy.) If the ball drops from a height of 9 m, then how high does it bounce back on the first bounce?
Question 16
The motor of a 1.8 kg battery-powered toy car creates a constant force of 0.80 N in the direction of motion. If the car starts from rest, then what is its speed after 1.5 m of forward motion? (You may assume no friction.)
Question 17
How much distance does it take to stop a car going 30 m/s (67 mph) if the brakes can apply a force equal to one-half the car's weight?
Question 18
The driver of a 1000 kg car traveling at 12 m/s suddenly sees a stop sign 70 m away. How much force must be applied using the brakes for the car to stop just in time?
Answers: 1
Physics, 22.06.2019 14:10, momo842
Your starship, the aimless wanderer, lands on the mysterious planet mongo. as chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 14.0 m/s returns to the ground in 5.70 s ; the circumference of mongo at the equator is 2.20Ă—10^5 km ; and there is no appreciable atmosphere on mongo. (a) the starship commander, captain confusion, asks for the following information: what is the mass of mongo? (b) if the aimless wanderer goes into a circular orbit 2.20Ă—10^4 km above the surface of mongo, how many hours will it take the ship to complete one orbit? (c) an unmanned spacecraft is in a circular orbit around the moon, observing the lunar surface from an altitude of 44.0 km . to the dismay of scientists on earth, an electrical fault causes an on-board thruster to fire, decreasing the speed of the spacecraft by 23.0 m/s . if nothing is done to correct its orbit, with what speed (in km/h) will the spacecraft crash into the lunar surface?
Answers: 1
Physics, 22.06.2019 17:00, StupidFatChipmunk
What equation is used to calculate the weight of an object on a plant ?
Answers: 1
Katie pushes on a 10 kg box with 70 N of force, but the box only accelerates by 3 m/s2. How much fri...
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