Answer: 6.36
Explanation:
Given
Radius of grindstone, r = 4 m
Initial angular speed of grindstone, w(i) = 8 rad/s
Final angular speed of the grindstone, w(f) = 12 rad/s
Time used, t = 4 s
Angular acceleration of the grinder,
α = Δw / t
α = w(f) - w(i) / t
α = (12 - 8) / 4
α = 4/4 = 1 rad/s²
Number of complete revolution in 4s =
Δθ = w(i).t + 1/2.α.t²
Δθ = 8 * 4 + 1/2 * 1 * 4²
Δθ = 32 + 1/2 * 16
Δθ = 32 + 8
Δθ = 40 rad/s
40 rad/s = 40/2π rpm = 6.36 rpm
Therefore, the grindstone does 6.36 revolutions during the 4 s interval
Answer:
Yes it is better to pull the rope rather than push it
Explanation:
Let the force is applied at an angle of 60 degree
so we will have net vertical force on the crate is given as
here we know
now friction force on the crate is given as
Yes it is better to pull the rope rather than push it
Airplanes produce lift from the air moving over their wings. Stall speed is a metric that refers to the minimum speed required for an airplane to produce lift. When airplanes fly slower than their respective stall speed, they won't produce lift. ... If an airplane's speed drops below its stall speed, it won't produce lift.
Answer:
7 miles northeast is the because it has both magnitude and direction .
