Force is a vector physical quantity that describes the interaction that occurs with an object to set it in motion or give it an acceleration. Newton's second law describes how force relates to the mass and acceleration of a body and is used to calculate its value. Generally speaking, the greater the mass of an object or body, the greater the force required to move it.
Steps
Part 1 of 2: Studying the Force Formula
Step 1. Multiply the mass by the acceleration
The force (F) necessary to be able to move an object of mass (m) by giving it an acceleration (a) is described by the following formula: F = m * a. So the force is equal to the mass multiplied by the acceleration.
Step 2. Convert the quantities under consideration using the international system (SI) units of measurement
The standard unit of measurement for mass is the kilogram (kg), while that of acceleration is meters per second squared, i.e. m / s2. When mass and acceleration are expressed according to the international system of units, a force expressed in newtons (N) is obtained.
For example, if the mass of an object is 3 pounds, you will first need to convert that value to kilograms. Three pounds is equal to 1.36 kg, so the mass of the object under consideration is 1.36 kg
Step 3. Remember that in physics, weight and mass refer to two different quantities
If the weight of an object is given in newtons (N), divide it by the coefficient 9, 8 to get the equivalent mass. For example, a weight of 10 N is equivalent to a mass of 10/9, 8 = 1.02 kg.
Part 2 of 2: Using the Force Calculation Formula
Step 1. Calculate the force required to deliver an acceleration of 5 m / s2 to a vehicle of 1,000 kg.
- Check all the data in your possession to verify that they are expressed with the correct units of measurement of the international system.
- Multiply the acceleration by 5 m / s2 for the mass of the vehicle (1,000 kg) to obtain the required value.
Step 2. Calculate the force required to accelerate an 8-pound wagon with 7 m / s2.
- First you will need to convert all the data under consideration into the correct units of measurement. One pound equals 0.453 kg, so you'll need to multiply that value by 8 to determine the mass of the object under test.
- Multiply the mass in kilograms (3.62 kg) by the required acceleration (7 m / s2) to obtain the necessary strength.
Step 3. Calculate the intensity of the force that must be applied to a shopping cart weighing 100 N so that it has an acceleration equal to 2.5 m / s2.
- Remember that 10 N equals 9.8 kg. So to convert newtons to kilograms you will need to divide them by 9.8 kg. The mass of the shopping cart in question, expressed in kilograms, will therefore be equal to 10.2 kg.
- Now multiply the new mass value (10.2 kg) by the acceleration (2.5 m / s2) and you will get the necessary strength.
Advice
- Always read the problem text very carefully to determine if the weight or mass value of the object under investigation is indicated.
- Check that all given values are expressed in the correct units of measurement: kg and m / s ^ 2.
- A newton, the standard unit of measure for force, is equal to 1 kg * 1 m / s ^ 2.
