You are working in a Christmas tree lot, moving trees. You can move a tree from the trimming area to a car in 20 seconds. The average tree requires 120
joules of work to move. Calculate your power.

The energy equivalent of the rest mass of an electron is

If a rock is thrown upward on the planet mars with a velocity of 10 mys, its height in meters t seconds later is given by y − 10t 2 1.86t 2 . (a) find the average velocity over the given time intervals: (i) [1, 2] (ii) [1, 1.5] (iii) [1, 1.1] (iv) [1, 1.01] (v) [1, 1.001] (b) estimate the instantaneous velocity when t − 1.

You have 80 g of 60oc water and 80 g or 10oc water. what is the final temperature when the two are mixed? explain.