CALCULATING FORCES OF MOTION

Not only is the universe stranger
than we imagine, it is stranger
than we can imagine.
Sir Arthur Eddington
(18821944)

Force
is a product of mass and acceleration.
You have practiced acceleration problems and now we will look at determining the amount of force that is applied to objects in motion. 
The equation for is
force = mass x acceleration
or
f = ma
Let's look at the steps for solving a force problem.
If you need to review solving one step multiplication problems,
click on link below.

Problem:
How much force must be applied to a toy car that has
a mass of .25kg to achieve an acceleration of
2.4m/s^{2}?

Step 1:
Write down the formula needed to solve
the problem.

f = ma

Step 2: Place the known measurements into the formula. 
Known
: The mass of the car is
.25kg and the acceleration of the
car is 2.4m/s^{2}.
f = (.25kg) (2.4m/s^{2})

Step 3:
Enter the numbers into
your calculator and solve.

f = .6N A force of .6N must be
applied to the toy car.

Now you can practice some problems on your own.

You will need to show all work set up in the equation. Don't forget
to label all numbers!
PROBLEMS: 
1. If a 4500 kg car is traveling westward with an acceleration of 35.2 m/s^{2},
what is the force acting on it?
2. I am a roller skater with a mass of 72kg. If I am accelerating toward a wall at 3.7m/s^{2}, what will be the amount of force at which I hit the wall? 3. A dock worker needs to stop a box of goods that is rolling across a manual conveyer belt. The box has a mass of 8.35kg and is accelerating at .75m/s^{2}. How much force will he need to apply to the box in order to stop it? 4. How much force must be applied to move a 55kg ice skater to an acceleration of 12.5m/s^{2}? 
Ready to try some problems that will challange you? Click here.
These problems are a bit tougher. Try these!