Answer:
Explanation:
F = mω²R
F = 15(2π/8.5)²(7.8)
F = 63.93044788...
F = 63.9 N
answer a) is the closest. No idea how they got a value that low unless they used a poor approximation for π.
Answer:
Man will not slide down
Explanation:
Given:
Coefficient of static friction = 0.25
Angle = 13°
Computation:
Man will slide down if
tan13° > Coefficient of static friction
Tan 13 = 0.23
So,
0.23 < 0.25
So,
Man will not slide down
Answer:
The distance to the moon greater than the distance across the Atlantic ocean by an order of 1.
Explanation:
We have the average distance across the Atlantic ocean, 
the average distance to the moon, 
The factor by which the distance to moon is greater than the width of Atlantic ocean:



i.e.
the distance to the moon greater than the distance across the Atlantic ocean by an order of 1.
Answer:
b. an electric current is used to turn the pointer of a galvanometer
Explanation:
well , galvanometer is an important device which is used to detect an electric current through a conductor or circuit.
something special about it is that it can detect very minute current too
Answer:
Mu,k between the floor and the box is 0.609
Explanation:
given information:
weight of the book, W = 325 N
applied force, F = 425 N
angle, θ = 35.2°
to find the coefficient kinetic between the floor and the box, wee need to calculate the horizontal and vertical force.
first we calculate the vertical force, there are weight, normal force(N) and applied vertical force.
according to Newton's first law
ΣF = 0
Σ
= 0
W - N + F sin θ = 0
N = W + F sin θ
Next, we calculate the force in horizontal direction. applied force and friction force(
)
Σ
= 0
F cos θ -
= 0
F cos θ - μk (W - F sin θ) = 0
μk = (F cos θ) / (W + F sin θ)
= (425 cos 35.2°)/(325+425 sin 35.2°)
= 0.609