Answer:
Explanation:
A free-body diagram is a sketch of an object of interest with all the surrounding objects stripped away and all of the forces acting on the body shown. The drawing of a free-body diagram is an important step in the solving of mechanics problems since it helps to visualize all the forces acting on a single object. The net external force acting on the object must be obtained in order to apply Newton's Second Law to the motion of the object.
A free-body diagram or isolated-body diagram is useful in problems involving equilibrium of forces.
Free-body diagrams are useful for setting up standard mechanics problems.
-- We're pretty sure that this question is based on an assumption of EARTH, so we know that we're dealing with a sphere of roughly 3.950 miles radius.
-- The distance on the sphere between 30° west and 60° east is 90° of longitude. That's 1/4 of the total circumference of the circle.
-- BUT ..... Way up here at 60° N latitude, the circle is not as big as the equator. It's radius/diameter/circumference is only cos(60°) = 0.5 of the Earth's total.
-- So the length of our quarter-circle arc is about
(1/4) x (2 · π · 3,950 miles) x (0.5) =
(1/4) x (3,950 π miles) =
988 π miles = 3,104 miles
Answer:
A
Explanation:
The magnet can always attract other things.
Answer:
the net toque is τ=8.03* 10⁻⁴ N*m
Explanation:
Assuming the disk has constant density ρ, the moment of inertia I of is
I = ∫r² dm
since m = ρ*V = ρπR² h , then dm= 2ρπh r dr
thus
I = ∫r²dm = ∫r²2ρπh r dr =2ρπh ∫r³ dr = 2ρπh (R⁴/4- 0⁴/4)= ρπhR⁴ /2= mR²/2
replacing values
I = mR²/2= 0.017 kg * (0.06 m)²/2 = 3.06 *10⁻⁵ kg*m²
from Newton's second law applied to rotational motion
τ= Iα , where τ=net torque and α= angular acceleration
since the angular velocity ω is related with the angular acceleration through
ω= ωo + α*t → α =(ω-ωo)/t = (21 rad/s-0)/0.8 s = 26.25 rad/s²
therefore
τ= Iα= 3.06 *10⁻⁵ kg*m²*26.25 rad/s² = 8.03* 10⁻⁴ N*m
