Mechanics | Relativity Answers

A 50.0 g Super ball travelling at 25.0 m/s bounces off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the magnitude of the average acceleration of the ball during this time interval?

On another planet, a marble is released from rest at the top of a high cliff. It falls 4.00 m in the first 1 s of its motion. Through what additional distance does it fall in the next 1 s?

A rock is thrown downward from the top of a 40.0m tall tower with an initial speed of 12 m/s. Assuming negligible air resistance, what is the speed of the rock just before hitting the ground?

An arrow is shot straight up in the air at an initial speed of 15.0 m/s. After how much time is the arrow moving downward at a speed of 8.00 m/s?

A cannon shell is fired straight up from the ground at an initial speed of 225 m/s. After how much time is the shell at a height of 102m above the ground and moving downward?

The intensity, I, of an electromagnetic wave is related to the electric field strength E and magnetic induction B of the fields producing it by the equation I = E.B / 20 where 0 is the permeability of free space. Show that this equation is homogeneous.

Two small spheres each suspended by a thread of small length, L from a common support have masses m and 2m respectively. Each sphere carries a net charge of +Q. Assuming that the angle the thread make with the vertical is small, and the distance, X between the spheres can be given by the equation X = (5KQ^2. L / 2mg)^1/3
Where g = acceleration due to gravity, K = 1 / 40 and 0 = permittivity of free space. Show that the equation is homogeneous.

A student taking a quiz finds on a reference sheet the two equations f = 1 / T and =square root of (1/T).
She has forgotten what T represents in each question.
Use dimensional analysis to determine the units required for T in each question.
Explain how you can identify the physical quantity each T represents from the units.

The position of a particle moving under uniform acceleration is some function of time, t and the acceleration, a. Suppose we write this position as x = ka^m.(t^n) where k is a dimensionless constant.
Determine the values of m and n.
Can this analysis give the value of k? Explain.

A garden hose is originally full of motionless water. What additional force is necessary to hold the nozzle stationary after the water flow is turned on if the discharge rate is 0.600 kg/s with a speed of 25.0 m/s?