A hockey puck slides horizontally off the edge of a table with an initial velocity of 20.0 m/s. The height of the table above the ground is 2.00 m. What is the magnitude of the vertical component of the velocity of the puck just before it hits the ground?
[A] 6.26 m/s
[B] 12.5 m/s
[C] 16.3 m/s
[D] 19.6 m/s
[E] 22.4 m/s
A 55-kg person steps on a scale in an elevator. The scale reads 460 N. What is the elevator doing?
[A] The elevator is in free fall.
[B] None of these.
[C] It is accelerating downward at 1.44 m/s2.
[D] It is stationary.
[E] It is accelerating upward at 0.41 m/s2.
An incompressible fluid flows steadily through a pipe that has a change in diameter. The fluid speed at a location where the pipe diameter is 8.0 cm is 1.28 m/s. What is the fluid speed at a location where the diameter has narrowed to 4.0 cm?
(A) 0.32 m/s
(B) 0.64 m/s
(C) 5.12 m/s
(D) 2.56 m/s
(E) 1.28 m/s
A motorcycle rider wants to try the following stunt: she will start from rest and accelerate her bike at constant acceleration a0 on a horizontal platform of length L; she will then jump with her bike trying to land on a second platform placed a distance y0 below the first one.
[a] What is the speed of the rider at the end of the first platform?
[b] What is the maximum distance at which the second platform can be placed for the rider to reach it?
[c] What is the speed of the rider when she reaches the second platform?
The velocity of an airplane as a function of time can be written as v(t) = bi − 3ct2j where b and c are positive constants. Provide your answers in terms of b, c, and t when necessary.
[a] What are the SI units of b and c?
[b] Find an expression for the position r(t) of the airplane as a function of time assuming that the airplane is at the origin at t = 0.
[c] Find an expression for the acceleration a(t) of the airplane as a function of time
[d] Find the trajectory of the airplane (y vs. x).