Physics 100A multiple choice final
A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a horizontal circle whose diameter is 1.0m. What is the magnitude of the net force on the ball?
100N
A force produces power P by doing work W in a time T. What power will be produced by a force that does six times as much work in half as much time?
12P
A child pulls on a wagon with a force of 75N. If the wagon moves a total of 42 m in 3.1 min, what is the average power delivered by the child?
17W
What magnitude net force is required to accelerate a 1200-kg car uniformly from 0m/s to 27.0 m/s in 100m?
4374N
If 4.0J of work are performed in stretching an ideal spring with a spring constant (force constant) of 2500 N/m, by what distance is the spring stretched?
5.7cm
If a net force accelerates a 4.5 kg box at 40m/s^2, what is the mass of another box if the same net force accelerates it to 30m/s^2
6.0kg
An object of mass 10.0 kg is initially at rest on a smooth surface. A 100N force causes it to move horizontally through the distance of 6.00m. What is the change in the kinetic energy of this object?
600j
An object moving in a straight line is slowing down. Which of the following statements about it must be true.
A net force is being applied to it in the direction opposite to the motion.
An object is moving with constant non-zero velocity. Which of the following statements about it must be true?
The net force on the object is zero.
An object of mass m rests on a flat table. The earth pulls down on this object with a force of magnitude mg. What is the reaction force to this pull?
The object pulling upward on the earth with force mg.
Identical forces act for the same length of time on two different objects. The magnitude of the change in momentum of the lighter object is
exactly equal to the magnitude of the change in momentum of the larger mass.
When an object experiences uniform circular motion. The direction of the net force is
is directed toward the center of the circular path
you are making a circular turn in your car on a horizontal road when you hit a big patch of ice, causing the force of friction between the tires and the road to become zero. While the car us on the ice, it
moves along a straight-line path in its original direction
A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the wall. Which one of these objects experiences the greater momentum change?
the ball