Select all that apply.

an acorn falls from a tree. which of the following statements is true?

the force of gravity is acting on the acorn.
the force of gravity is the only force acting on the acorn.
a frictional drag force is acting on the acorn.
the net force on the acorn is less than the force of gravity.

The x-coordinate of a particle in curvilinear motion is given by x = 3.1t3 - 4.9t where x is in feet and t is in seconds. the y-component of acceleration in feet per second squared is given by ay = 2.3t. if the particle has y-components y = 0 and vy = 5.0 ft/sec when t = 0, find the magnitudes of the velocity v and acceleration a when t = 1.8 sec. sketch the path for the first 1.8 seconds of motion, and show the velocity and acceleration vectors for t = 1.8 sec. answers: v = ft/sec a = ft/sec2

Suppose you have three polarizing filters, with the second at an angle of 42∘ to the first and the third at an angle of 90∘ to the first. by what perfect will the original intensity of unpolarized light be reduced to after passing through all three filters?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?