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If the force on an object is in the negative direction, the work it does on the object must be
The work could be either positive or negative, depending on the direction of the object's motion.
A truck has four times the mass of a car and is moving with twice the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that
Kt = Kc
Kt = 2Kc
Kt = 4Kc
Kt = 16Kc
Which of the following bodies has the largest
Mass 3M and speed V
Mass 3M and speed 2V
Mass 2M and speed 3V
Mass M and speed 4V
What are the KE and the GPE of the brick 1s after it is dropped?
KE = 80J and GPE = 0J
GPE = 68J and KE = 12J
KE = 40 J and GPE = 40 J
GPE = 30J and KE = 50J
What is the approximate speed of the brick 1s after it is dropped, if the mass is 1kg?
A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is
one-fourth as much
one-half as much
twice as much
four times as much
You lift a 3kg pumpkin to a height of 0.80 m to check it out. How much work do you do on the pumpkin when you lift it from the ground?
An intern pushes a 70-kg patient on a 10-kg gurney, producing an acceleration of 0.50 m/s2.
How does the amount of work change if the force is doubled and the distance is halved?
Which is true?
Gravitational force always does negative work on a vertically moving object as it always opposes motion.
Friction always does negative work on an object, as it always opposes motion
Both are true
To move a suitcase up to the check-in stand at an airport, a student pushes with a horizontal force through a distance of 0.90 m. If the work done by the student is 18 J, what is the magnitude of the force he exerts?
F = 20 N
F = 16.2 N
F = 34 N
F = 120 N
The kinetic energy of a small boat is 15000 J. If the boat’s speed is 5.0 m/s, what is its mass?
The gravitational potential energy of a person on a 3.0 m high diving board is 1800 J. What is the person’s mass?
The net force on an object changes with its position according to the force-position graph shown below. Find the work done between x = 0 m and x = 70 m.
How much work is done by a car if it changes its KE from 600J to 200J which applying its brake?