# Calculating power required

• 09-20-2018, 05:08 PM
idontcare
Calculating power required
Hello all,

I am a beginner in FSAE. Just started an FSAE team in college. I have doubts regarding calculating power required (kw). Its a basic conceptual doubt. Please help me understand it

If a vehicle is travelling at a constant velocity the power delivered is given as F.v, where F is the force required to overcome all the resisting forces of the car. correct?

Now if a vehicle is accelerating, some posts say, power delivered is (Ma)*Vavg, that is mass of the car * avg acceleration * avg Velocity. correct?
the same answer comes if calculated as change in kinetic energy per unit time
like in this example

Now in accelerating case ma = F(net) - F(all resistive force)

so power delivered by the engine should be F(net) * Vavg . Why is this wrong? Since Fnet is required to over come the resistive forces as well as create an extra force to accelerate the vehicle by a.

Please do clarify in as much detail as possible