Answer:
Explanation:
Given that,
Initial Angular velocity w=500rpm
Converting from rpm to rad/s
1rev =2πrad
1minutes =60secs
500rpm=500rev/mins
w = 500×2π/60
wi=52.36rad/s
The final angular velocity wf=0rad/s
Time to stop is t=2.6sec
We want to find angular acceleration α
Using the equation of angular motion
wf = wi + αt.
0 = 52.36 + 2.6α
-52.36=2.6α
α = -52.36/2.6
α = -20.14rad/s²
The angular acceleration is negative because it is decelerating.
Then, α=20.14rad/s²
Explanation:
V=40m/s
Vy=V.sina=40.sin20=40 . 0.342=13.68m/s
Vx=V.cosa=40.cos20=40 . 0.766=30.64m/s
Projectile travels during 5 seconds and the ramge becomes:
x=V.t=30.64 . 5=153.2m
I'm guessing that this is a problem to find the weight of a 90kg mass on a planet where the acceleration of gravity is 4 m/s^2. (Much less gravity than Earth, a little more than Mars.)
Just do the multiplication, and you get
360 Newtons.