## MATH - SCIENCE INTEGRATION

### Calculating Force

 Not only is the universe stranger than we imagine, it is stranger than we can imagine. Sir Arthur Eddington (1882-1944)

### Definition of Force

 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.

• Force Equation
 The equation for is force = mass x acceleration     or    f = ma The standard unit for mass is kg. The standard unit for acceleration is m/s2. The standard unit for force is newton (N).   A newton is a derived standard unit.  This means that the SI unit of newton is composed of two or more standard units.  1N = 1 kg x 1m/s2. 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.

» See also: Solving One Step Multiplication Problems

• Steps for Solving Force Equation
 Problem:   How much force must be applied to a toy car that has a mass of .25kg to achieve an acceleration of 2.4m/s2?

 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/s2. f = (.25kg) (2.4m/s2)

 Step 3:   Enter the numbers into your calculator and solve. f = .6N  A force of .6N must be applied to the toy car.

 Make sure that all of your numbers in the equation have a SI unit and make sure you label your answer with the correct SI unit for force (N).   Now you can practice some problems on your own.

• Force Practice Problems
 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/s2, 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/s2, 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/s2.  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/s2?