Force is an important concept in physics and is defined as a factor that changes the speed of an object or its direction of movement or rotation. A force can accelerate objects by pulling or pushing them. The relationship between force, mass and acceleration was defined by Isaac Newton in his second law of motion, which states that the force of an object is the product of its mass and acceleration. If you want to know how to measure strength, just follow these steps.
Steps
Method 1 of 2: Measure Strength
Step 1. Learn the relationship between force, mass and acceleration
The force of an object is simply the product of its mass and its acceleration. This relationship can be defined by the following formula: force = mass x acceleration.
Here are a few other things to keep in mind about how strength is measured:
- The standard unit for mass is kilograms (kg).
- The standard unit for acceleration is m / s2.
- The standard unit for force is the newton (N). Newton is a standard derived unit. 1N = 1 kg x 1 m / s2.
Step 2. Measure the mass of a given object
The mass of an object is the amount of matter it contains. The mass of an object never changes, no matter what planet you are on; while the weight varies according to the gravitational force, the mass is the same on the Earth and on the Moon. In the metric system, mass can be expressed in grams or kilograms. Suppose we are carrying out a problem on a truck that has a mass of 1000 kg.
- To find the mass of a certain object, you have to put it on the balance wheel or two-pan scale. This way you can calculate the mass in kilograms or grams.
- In the English system, mass can be expressed in lb. Since force can also be expressed in the same unit, the term "pound-mass" was coined to distinguish its use. However, if you find the mass of an object using pounds in the English system, it is best to convert it to the metric system. If you know the mass of an object in pounds, simply multiply by 0.45 to convert it to kilograms.
Step 3. Measure the acceleration of the object
In physics, acceleration is defined as a vector velocity variation, that is, a velocity in a given direction in the unit of time. In addition to the common definition of acceleration as an increase in speed, it can mean that an object is slowing down or changing direction. Just like speed, which can be measured with a speedometer, acceleration is measured with an accelerometer. Suppose the truck of mass 1,000 kg accelerates by 3 m / s2.
- In the metric system, speed is expressed in centimeters per second or meters per second, while acceleration is expressed in centimeters per second per second (centimeters per second squared) or meters per second per second (meters per second squared).
- In the English system, one way to express speed is feet per second, so acceleration can be expressed in feet per second squared.
Step 4. Multiply the mass of the object by its acceleration
This is the value of strength. Just insert the known numbers into the equation and you will find the strength of the object. Remember to write your answer in Newtons (N).
- Force = mass x acceleration
- Force = 1000 kg x 3 m / s2
- Force = 3,000 N
Method 2 of 2: Advanced Concepts
Step 1. You can find mass if you know force and acceleration by simply entering them into the same formula
Here's how to do it:
- Force = mass x acceleration
- 3 N = Mass x 3m / s2
- Mass = 3 N / 3m / s2
- Mass = 1 kg
Step 2. Find the acceleration if you know the force and mass of an object, simply by entering them in the same formula
Here's how to do it:
- Force = mass x acceleration
- 10 N = 2 kg x Acceleration
- Acceleration = 10 N / 2 kg
- Acceleration = 5m / s2
Step 3. Find the acceleration of an object
If you want to find the strength of an object, you must first calculate its acceleration and know its mass. All you have to do is use the formula to find the acceleration of an object. The formula is Acceleration = (Final speed - Initial speed) / Time.
- Example: A runner reaches a speed of 6 m / s in 10 seconds. What is its acceleration?
- The final speed is 6 m / s. The initial speed is 0 m / s. Time is 10 s.
- Acceleration = (6 m / s - 0 m / s) / 10 s = 6/10 s = 0, 6 m / s2
Advice
- Note that the relationship between force, mass and acceleration means that an object with low mass and high acceleration can have the same strength as an object with high mass and low acceleration.
- Forces can have special names depending on how they behave on an object. A force that causes the positive acceleration of an object is called "thrust", while if it causes a slowdown it is called "braking". A force that changes the way an object rotates around its axis is called a "torque".
- Weight is the expression of a mass subjected to the acceleration of gravity. On the Earth's surface, this acceleration is approximately 9.8 meters per second squared (9, 80665) or 32 feet per second squared (32, 174). Thus, in the metric system, a mass of 100 kg weighs about 980 N and of 100 grams weighs about 0.98 N. In the English system, mass and weight can be expressed in the same unit of measurement, so 100 kilos of mass (pound- mass) weighs 100 pounds (pound-force). Because a spring balance measures the force of gravity on an object, it actually measures weight, not mass. In common use, there is no distinction, as long as the only gravity under consideration is that of the surface of the Earth.
- Thus, a mass of 640 pound-mass accelerating by 5 feet per second squared exerts an approximate force of 640 x 5/32, or 100 pound-force.
- Mass can be expressed in slugs, which equals 32, 174 pound-mass. A slug is the amount of mass that 1 pound-force can accelerate by 1 foot per second squared. When the mass in slug is multiplied by the acceleration in meters per second squared, the conversion constant is not used.
- A mass of 20 grams accelerating by 5 centimeters per second squared carries a force of 20 x 5 = 100 gram-centimeters per second squared. The gram-centimeter per second squared is called dyne.
- Divide the result by a conversion constant if you are working with English units. As noted above, "pound" can be a unit of both mass and force in the English system; when used as a unit of force, it is called "pound-force". The conversion constant is 32, 174 pound-feet-per-pound-force per second squared; 32, 174 is the value of the acceleration of earth's gravity in meters per second squared. To simplify the calculations, we can round to a value of 32.
- A mass of 150 kg accelerating to 10 meters per second squared exerts a force of 150 x 10 = 1,500 kg-meters per second squared. One kilogram meter per second squared is called a newton.
