Answer:
a)- 1.799 rad/sec²
b)- 17.6 x 10ˉ³Nm
Explanation:
ω₀ = 720 rev/min x (1 min/60 sec) x (2π rad / 1 rev) = 24π rad/s
a) Assuming a constant angular acceleration, the formula will be
α = (ωf -ω₀) / t
As final state of the grindstone is at rest, so ωf =0
⇒ α = (0-24π) / 41.9 = - 1.799 rad/sec²
b)Moment of inertia I for a disk about its central axis
I = ½mr²
where m=2kg and radius 'r'= 0.099m
I = ½(2)(0.099²)
I = 9.8 x 10ˉ³ kgm²
Next is to determine the frictional torque exerted on the grindstone, that caused it to stop, applying the rotational equivalent of the Newton's 2nd law:
τ = I α =>(9.8 x 10ˉ³)(- 1.799)
τ = - 17.6 x 10ˉ³Nm
(The negative sign indicates that the frictional torque opposes to the rotation of the grindstone).
Please remember to post in the right category next time :)
.40 as a fraction is 4/10 or 2/5
the 4 is in the tenths place, so put it over a 10 to make it a fraction.
then, simplify the fraction by dividing the numerator and denominator by 2, and you get 2/5
Answer:
B) they have been proven to cause drowsiness
Explanation:
B is the only answer that makes sense, as the other answers do not make sense. All medications are scientifically tested before they can be used by someone. Covering their bases would show negligence and is bad.
Hope this helps!
PS, this is biology or medical, not physics.
