Question

An advertisement claims that a certain 1200 kg car can accelerate from rest to a speed of 25 m/s in a time of 8 s. What average power the motor produce to cause this acceleration? (Ignore friction losses)

Answer 1

\[Power = Force \times Velocity\]

Answer 2

How do i use this formula?

Answer 3

You are given mass, you can solve for acceleration. Therefore you can find Force. You need to find average velocity which is 25/2.

Answer 4

u know
\[power=\frac{ work }{ time }\]

Answer 5

so we can write
\[p=\frac{ w }{ t }\]

Answer 6

but
\[w=FS\]

Answer 7

F=force
S=displacement

Answer 8

so
\[p=\frac{ FS }{ t }=F*\frac{ S }{ t }=F*V\]

Answer 9

v= velocity

Answer 10

anyway use
\[w=FS=mas\]

Answer 11

a=acceleration

Answer 12

\[a=\frac{ v-u }{ t }=\frac{ 25-0 }{ 8 }\]

Answer 13

use
\[v ^{2}=u ^{2}+2aS\]

Answer 14

S=?

Answer 15

plz feel free to ask