Average Resistive Force Calculator:
Enter the values of mass, m(kg), velocity (V(m/s) = Vi(m/s) – Vf(m/s) ) and time, t(s) to determine the value of average resistive force, ARF(N).
Average Resistive Force Formula:
The average resistive force is the force that results in a change in velocity of an object over a given time period, often due to resistance such as friction or air resistance.
Average resistive force, ARF(N) in Newtons is calculated by multiplying the mass, m(kg) in kilograms by the change in velocity (V(m/s) = Vi(m/s) – Vf(m/s) ), where Vi(m/s) is the initial velocity and Vf(m/s)is the final velocity in metres per second and dividing by the time, t(s) in seconds over which the change occurs.
Average resistive force, ARF(N) = m(kg) * (Vi(m/s) – Vf(m/s) ) / t(s)
ARF(N) = average resistive force in Newtons, N.
m(kg) = mass in kilograms, kg.
Vi(m/s) – Vf(m/s) = change in velocity in metres per second, m/s.
t(s) = time in seconds, s.
Average Resistive Force Calculation:
1. A skateboarder with a total mass of 70 kg slows down from 15 m/s to 5 m/s in 3 seconds due to friction.
Given: m(kg) = 70kg, Vi(m/s) = 15m/s, Vf(m/s) = 5m/s, t(s) = 3s.
Average resistive force, ARF(N) = m(kg) * (Vi(m/s) – Vf(m/s) ) / t(s)
ARF(N) = 70 * ( 15 – 5 ) / 3
ARF(N) = 233.33N.
2. A vehicle with a mass of 1200 kg decelerates from 30 m/s to 10 m/s. If the average resistive force experienced by the vehicle is 6000 N, find the time over which this deceleration occurs.
Given: m(kg) = 1200kg, Vi(m/s) = 30m/s, Vf(m/s) = 10m/s, ARF(N) = 6000N.
Average resistive force, ARF(N) = m(kg) * (Vi(m/s) – Vf(m/s) ) / t(s)
t(s) = m(kg) * (Vi(m/s) – Vf(m/s) ) / ARF(N)
t(s) = 1200 * ( 30 – 10 ) / 6000
t(s) = 4s.