Answer:
The necessary information is if the forces acting on the block are in equilibrium
The coefficient of friction is 0.577
Explanation:
Where the forces acting on the object are in equilibrium, we have;
At constant velocity, the net force acting on the particle = 0
However, the frictional force is then given as
F = mg sinθ
Where:
m = Mass of the block
g = Acceleration due to gravity and
θ = Angle of inclination of the slope
F = 5×9.81×sin 30 = 24.525 N
Therefore, the coefficient of friction is given as
24.525 N = μ×m×g × cos θ = μ × 5 × 9.81 × cos 30 = μ × 42.479
μ × 42.479 N= 24.525 N
∴ μ = 24.525 N ÷ 42.479 N = 0.577
Matt Biondi..?
(I don’t know if it’s right, sorry if it is wrong)
:)
Answer: B. Concrete
Explanation:
Let N = reacting force pressing the bodies in context together (units in Newtons),
The question stated that the force pressing the two mounted/stacked objects together is equal to the weight of the object on top.
We need to start by finding the weight of the piece of wood.
friction is given by
f = μN
The value of f is 22.5,
and from the chart reference the coefficient of friction between wood and stone, μ is 0.30.
22.5 = 75. 0.30
Putting the values into the equation: 22.5 = 0.30N.
Divide both sides by 0.30 to find the value of N:
N= 22.5/0.3 = 75
Now that the piece of wood will be placed on another surface, its weight of 75 Newton is the force pressing the two bodies together.
To determine the new surface, you should find the new coefficient of friction by using the new value of the force of friction given 46.5:
46.5 = µ(75).
Divide both sides by 75 to isolate μ.
The refer chart also indicates that the coefficient of friction equals 0.62 between wood and concrete, so the new surface corresponding to 0.62 is the concrete, which is (B).
Gravity is one of the significant forces of the universe. It is the force that draws other objects closer to the center of another object. The bigger the object, the higher its force of gravity and nearby objects are accelerated towards the big mass.
It is this force of gravity that keeps the planets in the solar system orbiting around the sun. The suns gravitational pull is stronger than those of the planets hence pulls the planets on their orbits around the star. Gravity also played a part in the formation of the planets. Gravity caused the condensation of dust and rocks into a mass that continually attracted more matter as it gained mass (due to gaining more associated gravitational pull).
The astrometric technique of planet detection works best for massive planets around nearby stars.
