A force is typically a vector quantity. Thus, it is a quantity, which has both the magnitude and the direction. In order to describe the force acting upon an object, we are required to explain both the magnitude as well as the direction. The average force is the force imposed by some object moving at a certain rate of speed i.e. velocity for a certain period of time.
The term average in this context is used to suggest that this is not an immediate or precisely measured velocity. Hence, the average force will be equivalent to the mass of the body multiplied by the average velocity of the object over a specified time.
Formula for Average Force
The mass of the object multiplied by the average velocity over the definite time is equal to the average force. For a specific interval of time t, the force is explained as the frequency of change of momentum. It is not easy to identify the rate of change if the time interval is short.
Over a period of intervals Δt, the rate of change of momentum will be the Average force. It is written as:
F = m (Vf–Vi)/Δt
F= the average force
M = mass
Vf = final velocity
Vi = initial velocity
Formula of Magnitude of Force
Magnitude of force formula = FNET - = ma
What is a Net Force?
When we kick a football, the ball blows and moves through the air. During this, there is a net force acting on the ball. When the ball begins to come back to the ground and ultimately stops, there is a net force acting upon the ball as well. As per Newton's Second Law, when a net force is acting on an object, then that object must be accelerating, meaning that its speed changes from second to second.
Solved Examples Using Average Force Formula
A man throws an object with a mass of 7 kg and it rolls with a velocity of 4 m/s for 2 s. Find out its average force?
Given: Mass of bowling ball m = 7 kg,
Initial velocity vi = 0
Final velocity vf = 4 m/s
Plugging in the values in the Average force formula, we have:
F = m (vf – vi)/Δ t
F = 7 (4-0)/2
F= 14 N
A rabbit that weighs 20 kg chases the owner for 16 seconds with a velocity of 7 m per sec. Calculate the average force for the dog?
The mass’ m = 20 kg.
The rabbit’s average velocity, Vavg = 7 m per s
The time, Δt =16seconds.
Now, the formula is,
F = m (Vf–Vi)Δt
= 140kgmpers / 16sec
= 8.75 kg m per s²
Hence, the average force is 8.75N.