A 65-kg person on in-line skates pushes against a wall, and recoils with an acceleration of 3.3 m/s2. What force does the wall exert on the person?

Which notation is used to represent an alpha particle? a. b. c. d.

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

In a good thermo flask the main cause of heat loss is