# HELP. exam tomorrow. practice midterm questions

1. Oct 23, 2008

### taproot729o6

Two problems.
Problem 1. (30 Points)

When leaving for work, a woman leaves a cup of coffee on top of her car. The cup stays
fixed on the car, and the car moves according to the function:

x(t) = (2.0 m/s) t + (1.0 m/s2) t2

At time t = 2.0 s, a gust of wind comes from behind the car and blows the cup of coffee
off the car with a velocity of v = 5 m/s at an angle θ = 30° from horizontal. The coffee
cup strikes the ground after some time.

(a) What are the magnitudes of the velocities of (i) the car and (ii) the coffee when
the coffee flies off the car? (20 Points)
(b) Where does the coffee land with respect to the car? (Take the initial position of
the coffee to be the very front of the car.) (10 Points)

Problem 2. (30 Points)

A block with m=1.00 Kg sits d= 5.00 m from the edge of a platform. A constant
force of magnitude F=50.0 N is applied to the block at the angle of θ = 10° below
the horizontal. The applied force stops when the block reaches the edge of the
platform. The block lands a distance of l = 15.0 m from the platform. What is the
height of the platform, h? Assume all the surfaces are frictionless.

2. Oct 24, 2008

### alphysicist

Hi taproot729o6,

From the thread title, you may not be interested in these problems anymore. If you are, please show what you have tried so far, so that we can see how to help.