A 10-g penny is dropped from a building that is 125m high. The penny is initially at rest. Approximately how long does it take the penny to hit the ground?
What is 4.5/5.0 seconds (depending on what gravity value)
100
A car travels at a constant velocity of 30 m/s. The mass of the car is 1,000 kg. The forward force of the road on the car is 1,000 N. What is the total amount of backward force on the car from drag and rolling friction?
What is 1000 N
100
How much work is done to accelerate a 5.0 kg object from 6.0 m/s to a speed of 12 m/s?
What is 270 J
100
A 193 kg curtain needs to be raised 7.5 m, at constant speed, in as close to 5.0 s as possible. The power ratings for these three motors are listed as 1.0 kW, 3.5kW, and 5.5 kW. Which motor is best for the job?
What is 3.5 kW
100
A mover uses a pulley system to lift a grand piano with a mass of 500 kg from the ground to a height of 10 m. What is the change in the piano's gravitational potential energy?
What is 50000 J
200
A cannonball is launched at an angle and travels above flat ground. At what time point does the projectile reach its maximum height?
What is one half the total time in the air
200
A skier weighing 70 kg pushes off from the top of a ski slope with a force of 105 N directed down the slope. The slope is inclined at 30 degrees. assuming that the slope is frictionless, what is the initial rate of the skier's acceleration during the push-off?
What is 6.5 - 7.0 m/s ^2
200
A boy pulls a 10 kg box across an ice rink for a distance of 50 m. He exerts a constant force of 10 N on a rope attached to the box at an angle of 60 degrees. How much work has he done on the box?
What is 250 J
200
A man pushes a 100 kg box with a horizontal force of 100 N across a floor for a distance of 60 m in 2 min. What is his power?
What is 50 W
200
A spring is stretched 5 cm. What happens to its elastic potential energy if it is stretched 20 cm?
What is 16 times greater
300
A placekicker kicks a football at a velocity of 10.0 m/s from a tee on the ground at an angle of 30 degrees from the horizontal. Approximately how long will the ball stay in the air?
What is 1.0 seconds
300
Object A, when acted upon by a force F, accelerates at a rate of 4.0 m/s/s. This same force accelerates Object B at a rate of 8.0 m/s/s. Compared to the mass of Object A, the mass of Object B is
What is one-half as great
300
A 2000 kg car accelerates from rest under the actions of two forces. One is a forward force of 1140 N provided by the traction between the wheels and the road. The other is a 950 N resistive force of friction. Determine how far the car must travel for its speed to reach 2.0 m/s.
What is 21 m
300
A man pushes a lawn mower with a handle at an angle of 60 degrees to the horizontal. He applies a constant 20 N force along the axis of the handle and moves the lawn mower a horizontal distance of 100 m in 5 min. What his the man's power output?
What is 3 W
300
An object has 50 J of gravitational potential energy when it is 10 m off the ground. How much kinetic energy will a twice-as-massive object have if it is held 20 m off the ground?
What is 200 J
400
An airplane is flying horizontally at a velocity of 50/0 m/s at an altitude of 125m. It drops a package to observers on the ground below. Approximately how far will the package travel in the horizontal direction from the point that it was dropped?
What is 250 meters
400
A girl pushes a 10-kg box from rest across a horizontal floor with a force of 50 N. The force of friction opposing her is 45 N. If the box uniformly accelerates from rest to a final velocity of 2.0 m/s, how much time did it take to get to the velocity?
What is 4 seconds
400
An object initially at rest. A force of 2.0 N is excepted on an object for 5.0 m increases the object's velocity by 1.0 m/s. What is the mass of the object?
What is 20 kg
400
How long does it take a 19 kW steam engine to do 6.8 x 10^7 J of work?
What is 3600 s or 1 hour.
400
Spring 1 is stretched and stores 2 J of elastic potential energy. An identical spring, Spring 2, is stretched and stores 18 J of elastic potential energy. What is the ratio of the displacement of spring 2 to the displacement of spring 1?
What is 3:1
500
A car is traveling at an unknown velocity. It accelerates constantly over 5.0 seconds at a rate of 3.0 m/s^2 to reach a velocity of 30 m/s. What was the original velocity of the car?
What is 15 m/s
500
A 1,000-kg car is initially traveling at 30 m/s. The driver applies the brakes suddenly, and the friction exerts 9,000 N of force on the car. If the car uniformly negatively accelerates to a complete stop, how far does the car travel during the braking process?
What is 50 meters
500
A rifle a 4.0 g bullet at a velocity of 950 m/s. If the length of the rifle barrel is 1.01 m, then what force does the rifle except on the bullet?
What is 1,800 N
500
A rain cloud contains 2.66 x 10^7 kg of water vapor. How long would it take for a 2.00 kW pump to raise the same amount of water to the cloud's altitude, 2.00 km?
What is 8.27 years or 2.61 x 10^8 seconds
500
A 5 kg box slides down a frictionless incline from a vertical height of 10 m. The box starts from rest. What is the box's velocity at the bottom of the hill?