1. VECTOR APPLICATIONS Dr. Shildneck

2. WORK

3. Example 1 A child is pulling a sled along level ground by exerting a force of 100 Newtons on a rope that makes an angle of 35 o with the horizontal. How much work is done pulling the sled 200 meters? Note: the unit we get for work is a N-m (Newton-Meter) which is called a Joule (J).

4. Example 2 A boat is sitting on a slope of 20 o. If the boat weighs 2250 pounds. (a) Find the force needed to hold the boat still on the ramp. (b) Find the force holding the boat against/into the ramp.

5. Example 3 Two people are pulling on a cart with a rope. The first is pulling with a force of 45 pounds. The second is pulling at a force of 50 pounds. If the two people are pulling in directions 15 o apart, (a) At what force are they pulling? (b) At what angle (compared to the first person) is the cart moving?

6. Example 4 Three forces are acting in different directions on the same object such that the object is not moving (at equilibrium). The first force of 50 pounds is at an angle of 100 degrees from a 20 pound force. Another force is 110 degrees from the 20 pound force and 150 degrees from the 50 pound force. Find the size of the third force.