- 14

- 0

**1. The problem statement, all variables and given/known data**

A car engine accerlates from 1080rpm to 4800rpm in 12.5 seconds. Calculate the angular accleration, assumed constant, and the total number of revolutions the engine makes in this time

**3. The attempt at a solution**

angular acceleration (a) = (wf - wi) /(tf - ti)

(a) = (160 - 36) π / 12.5 = 31.15 rad/s^2

angle moved = θ = wi * t + 0.5 at^2

θ = 36 π *12.5 + 0.5 [124 π / 12.5 ] [12.5]^2

θ = 450 π + 0.5 [124 π] 12.5

θ = 450 π + 775 π = 1225 π

θ = [1225/2] [2π] = N[ 1 revolution]

N = numberof revolutions made = N = 1225/2 = 612.5

DID I DO THIS RIGHT?