a man begins pushing a lawn mower across a lawn from a standing start. which of the following is true?

a. you cannot tell whether the kinetic energy of the lawn mower is increasing or decreasing from the information given b. the man is decreasing the kinetic energy of the lawn mower
c. the kinetic energy of the lawn mower is not changing.
d. the man is increasing the kinetic energy of the lawn mower

Ineed asap! list 3 examples in which friction us or makes things easier in our daily life. explain the effect of friction for each. *make sure you explain the effect of friction for each example! *

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Abeam of electrons moves at right angles to a magnetic field of 4.5 × 10-2 tesla. if the electrons have a velocity of 6.5 × 106 meters/second, what is the force acting on the electrons? the value of q = -1.6 × 10-19 coulombs.