SPH 3U __TEST REVIEW: DYNAMICS__

__TEST DATE: Wednesday,
Oct 16__

__DYNAMICS TEST
OUTLINE:__

A. __Newton’s Three Laws: __

Memorize each law and be prepared to answer question(s) applying each
law to some situation such as a car crash or amusement park ride.

B. Problems: resolving two forces which are (a) linear, (b) at right angles
to each other

C. Bodies
in Equilibrium Problem: resolving three forces which are in
equilibrium (ΣF = 0) forming a closed triangle

D. Basic friction problems using F_{f
}=μ F_{N}

E. Problems combining uniform acceleration,
friction, and Newton’s Second Law.

F. A basic problem involving the Law of Universal Gravitation

1. A child is pulling a 10 kg wagon along with a force of 20 N [east] on a road with a frictional force of 5 N. Calculate:

acceleration
of the wagon. (3 marks)
1.5 m/s^{2} [E]

2.

3. Two people are having a tug-of-war. Person "Y" is pulling 200 N [north] nand person "X" is pulling at 100 N [east.] Their ropes are attached to to mass "A" which is resting on a frictionless tabletop. Mass A is 20 kg. Find the acceleration of mass A. (5 marks) ________

4. Three children are pulling on ropes as described below. Child A is pulling at 40 N [east], child B is pulling at 30 N [north] Calculate the magnitude and direction of force. AC@ if the forces are balanced. (ie: the system is not moving)

5.
For each of **Newton’s
First Law, Newton****=s Second Law** and **Newton****=s Third Law:**

State the law. Describe an example of each law which you would experience as a passenger in any amusement park ride (such as the tilt-a whirl or a roller coaster) (12 marks) For the test, be sure to memorize Newton's Laws (all postulatles). Check out the section on "Newton's Laws" in chapter 1 of your text for more information on the applications of Newton's Laws.

5. A 1.0 kg cart is pushed along with an initial velocity of 2.0 m/s. It it released and it coasts to a stop in 3.0 s. What is the coefficient of friction between the two surfaces? coefficient of friction is 0.068

6.
A 0.5 kg object is pushed along horizontally with an applied force of 10 N. If the object starts from rest and accelerates to 8.0 m/s in 6 seconds, what is the __coefficient of friction__ between the two surfaces?
coefficient of friction is 1.9 (note: this is a really __large__ value)