Physics 1100

Test #2

19 February 2002

1. [10] A ball rolls with velocity of v = 6.00 m/s² off the flat roof of a 20-m tall building. A boy is standing 25 m from the side of the building. The boy starts running to catch the ball the instant it rolls off the roof.  If the boy runs at constant velocity, how fast must he run to just catch the ball. Ignore the boy’s height.
2. [10] A physics teacher is conducting an experiment in an elevator.  The elevator is accelerating upwards at b = 1.00 m/s².  At the same time, the teacher is pulling a horizontal string that is attached to a block of mass 10.0 kg.  The block in on a large weigh scale that is sitting on the floor of the elevator. The teacher observes the acceleration of the block to be 2.20 m/s² horizontally.  Find the reading on the scale and the tension in the string. The coefficients of static and kinetic friction are 0.32 and 0.21 respectively.

3. [6] Some of the FBDs below may have problems. Explain what they are if any.

4. [4] A sprinter bursts from the starting line with horizontal acceleration.  Draw the FBD for the sprinter.  Which force is accelerating the sprinter?  Explain how you know that this is the force responsible.  Ignore air resistance.

		sin(2θ) = 2sin(θ)cos(θ)

Quadratic Equation
Given the formula , the solutions are

Questions? mike.coombes@kpu.ca