Physics

How does acceleration of an object change in relation to its mass?

inversely proportional

A rock is thrown vertically into the air. At the very top of it trajectory the net force on it is

its own weight

A tennis ball and a solid steel ball with the same diameter are dropped at the same time. Which ball has the greater force acting on it?

steel ball because it has more mass

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. The reason this can be done is that

the milk carton has inertia

Describe the forces acting on an object in equilibrium.

the net force is a sum of 0, sum of the forces in x and y directions are 0, and the forces will be balances

tennis ball and a solid steel ball with the same diameter are dropped at the same time. In the absence of air resistance, which ball has the greater acceleration?

they will have the same acceleration

How much does a 3.0-kg bowling ball weigh on Earth?

w=mg =(3.0)(9.81)=29.4 N

After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals

zero, no force is necessarily needed for something to continue moving

An object weighs 30 N on Earth. A second object weighs 30 N on the moon. Which has the greater mass? (Note: g on the moon is about 1/6 of g on earth)

One on the moon

Two people pull on a rope in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?

400 N

A person is attracted towards the center of Earth by a 440-N gravitational force. The force with which Earth is attracted toward the person is

440 N

A sledge hammer delivers a blow of 5000 N to a nail. The force that acts on the hammer during this hit

5000 N

A book weighs 4 N. When held at rest in your hands, the net force on the book is

0 N

An apple weighs 1N. The net force on the apple when it is in free fall is?

1 N

A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10 kg brick one would have to push with how many times the original force?

10 times

A box is dragged without acceleration in a straight-line path across a level surface by a force of 13 N. What is the magnitude of the frictional force between the box and the surface?

13 N

Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. What does the particle do?

The particle will continue at the force it was when it encountered the 2nd force

If your car runs out of gas, why can't you push on the car's windshield from the inside to move it?

an outside force must be exerted on a car in order to move

The law of inertia applies to (a)objects at rest (b) objects in motion (c) both moving and nonmoving objects

both moving and nonmoving objects

A clothesline is stretched between two trees. A tire hangs in the middle of the line and the two halves of the line make equal angles with the horizontal. The tension in the line is (a)half the tires weight (b) less than half the tires weight (c) more than half the tires weight

c- more than half the tires weight