The diagram shows the electric field lines around two charges. Based on the field lines, what is the best description of the charges?

a) They are negative, and they repel.
b) The left is negative and the right is positive, so they attract.
c) The left is positive and the right is negative, so they attract.
d) They are positive, and they repel.

Suppose you use a machine that gives you a mechanical advantage of 2 to achieve an output force of 30newtons what must the input force be

Using the work energy theorem. what is the velocity of a 850kg car after starting at rest when 13,000j of work is done to it.

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s