A crate moves to the right on a horizontal surface as a woman pulls on it with a 10-N force. Rank the situations shown below according to the work done by the 10-N force, least to greatest. The displacement is the same for all cases

The work done by gravity during the descent of a projectile is: positive
negative
zero
sign depends on the direction of the y axis
sign depends on the direction of both the x and y-axes

The velocity of a particle moving along the x-axis changes from v_i to v_f. For which values of v_i and v_f is the total work done on the particle negative

v_i=2m/s, v_f = 5m/s
v_i = -2m/s, v_f = 5m/s}_
v_i = -2m/s, v_f = -5m/s
v_i = 2m/s, v_f = -5m/s}
v_i = -5m/s, v_f = 2m/s

The amount of work required to stop a moving object is equal to the:

velocity of the object

kinetic energy of the object
mass of the object times its acceleration
mass of the object times its velocity
square of the velocity of the object