A person steps on to a scale in a stationary elevator and notes their weight. The elevator begins to accelerate downward. While the elevator accelerates downward, the scale reads: the same as when it is stationary more information is needed less than when the elevator is stationary more than if the elevator were accelerating upward more than when the elevator is stationary

A large box is being pushed across the floor at a constant speed of 4.0 m/s. What can you conclude about the forces acting on the box? The amount of force applied to move the box at constant speed must be more than its weight The amount of force applied to move the box at constant speed must be more than the amount of the frictional forces that resist its motion O The amount of force applied to move the box at constant speed must be equal to the amount of frictional forces that resist its motion There is a force being applied to the box to make it move but the external forces such as friction are not "real" forces they just resist motion O If the force applied to the box is doubled, the constant speed of the box will double to 8.0 m/s

Which one of the following forces is non-conservative? O The electric force The Elastic force O The gravitational force O Air resistance

A crate with mass m = 20 kg is being pushed to the right by a force of magnitude F = 80 N The crate is placed on a rough horizontal coefficient of kinetic friction surface with a HK= 0.2 Take g = 10 m/s² The acceleration of the crate is: 3.8 m/s^2 O 2 m/s^2 O 6 m/s^2 4 m/s^2

Find the net work done on the box as it moves from x = 0 m to x = 8.0 m. . ΑΣφ ? Submit Request Answer Part B Apply concepts of work and energy to solve for the speed of the box when it reaches position x = 8.0 m. Assume the box started from rest. ? m/s Submit Request Answer

Problem 5: In the two cases shown below, a person is standing on a scale in an elevator. The elevators are identical, and the person weighs 500 N. In both cases the elevator is moving upward, but in Case A it is accelerating upward and in Case B it is accelerating downward. A B y = 3 m/s v = 3 m/s a=2 m/s? a=2 m/s? Will the scale reading in Case A be greater than, less than, or the same as the scale reading in Case B? Explain with a calculation or in words.

The Earth pulls downward on a pingpong ball with a force  of 1N. If this is the "action" force, what is the "reaction" force? answer choices The ground exerts a force of 1N on the ping pong ball The ping pong ball exerts a force of 1 N on the Earth The ping pong ball pushes down on the earth with a force of 1N The is no reaction force when a gravitational force is involved

A person stands on a scale inside an elevator at rest (see the figure below). The scale reads W = 625 N. a W (a) What is the person's mass? kg (b) The elevator accelerates upward momentarily at the rate of a = 4 m/s?. What does the scale read then? N (c) The elevator then moves with a steady speed of 6 m/s. What does the scale read now?

A 35-N crate slides down a frictionless incline that is 25° above the horizontal. The magnitude of the normal force of the incline on the crate is closest to O 11 N 23 N O 32 N non eof the above

Which of the following is TRUE about frictional force?     Frictional force always opposes motion     Frictional force sometimes opposes motion     Frictional force speeds up the motion     Frictional force sometimes speed up motion     Frictional force can both speed up and slow down a motion