Which of the following is an example of static friction? a. rubbing sticks together to create a fireb. a marble rolling down a streetc. leaning against a rock to take a break. d. a hockey player shooting a puck into the goal.

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

Compare the patterns of the two waves shown in the image. which statement is true about these waves?

The process of a material going through a change of state from a gas to a liquid