A ball is thrown upward and let fall down a building. Another identical ball was dropped straight down the building at the same time with the same initial speed as the first ball. How will the velocities of these two balls compare when they each hit the ground? Justify your response.

Iwill give 30 points to whoever answers ! what is the formula for actual mechanical advantage and ideal mechanical advantage?

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".