Acar of mass 1200 kg is traveling at 2 m/s. then it collides with a heavy boulder in the road. during the collision, the car moves forward only 15 cm before stopping. what is the average force exerted by the boulder on the car?
1.6 x 104 n
3.2 x 104 n
5.4 x 104 n
6.5 x 105 n
1.8 x 104 n

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

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.

Frank just graduated from eighth grade. assuming exactly four years from now he will graduate from high school how many seconds does he have until his high school graduation