Physics(Please help)
posted by Hannah on .
A dentist causes the bit of a highspeed drill to accelerate from an angular speed of 1.44 x 104 rad/s to an angular speed of 5.05 x 104 rad/s. In the process, the bit turns through 1.77 x 104 rad. Assuming a constant angular acceleration, how long would it take the bit to reach its maximum speed of 8.95 x 104 rad/s, starting from rest?
Do I start by subtracting the two angular speeds?

ω=ωₒ+ε•t,
t= (ωωₒ)/ε……..(1).
Plug (1) in following
φ =ωₒ•t +ε•t²= (ω²ω²ₒ)/2•ε .
ε= (ω²ω²ₒ)/2• φ =(25.52.07) •10^8/2•1.77•10^4 =6,32•10^4 rad/s²
Now,
ω1=ωₒ+ε•t1,
t1 = (ω1ωₒ)/ ε =(8.950) •10^4/ 6,32•10^4 =1.42 s.