Physics 1: Kinematics
A Jogger runs with constant speed through a forest of pine trees. A pine cone starts to fall from a height when the jogger is directly below it. How far behind the jogger will the pine cone land?
In a rescue attempt, a hovering helicopter drops a life preserver to a swimmer being swept downstream by a river current of a constant velocity v. The helicopter is at a height of 9.8 m. The swimmer is 6.0 m upstream from a point directly under the helicopter when the life preserver is released. It lands 2.0 m in front of the swimmer. How fast is the current flowing? Neglect air resistance.
13.7 m/s
9.8 m/s
6.3 m/s
2.8 m/s
A child tosses a ball directly upward. Its total time in the air is T. Its maximum height is H. What is its height after it has been in the air at time T/4? Neglect air resistance.
H/4
H/3
H/2
2H/3
3H/4
A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 18.0 m/s. The cliff is 50.0 m above a flat, horizontal beach as shown in the figure. (a) What are the coordinates of the initial position of the stone? (b) What are the components of the initial velocity? (c) Write the equations for the x- and y-components of the velocity of the stone with time. (d) Write the equations for the position of the stone with time, using the coordinates in the figure. (e) How long after being released does the stone strike the beach below the cliff? (f) With what speed and angle of impact does the stone land?