Answer:
W = 7000 J
Explanation:
To solve this problem we use that the speed of the bicycle is constant, therefore its acceleration is zero
F -fr = 0
F = fr
where F is the force applied by the child
Work is defined by
W = F. x
W = F x cos θ
in this case the child's force is parallel to the movement, therefore the angle is zero and cos 0 = 1
let's calculate
W = 35 200
W = 7000 J
Answer:
0.76
Explanation:
we are given:
radius (r) =5.7 m
speed (s) = 1 revolution in 5.5 seconds
acceleration due to gravity (g) = 9.8 m/s^{2}
coefficient of friction (Uk) = ?
we can get the minimum coefficient of friction from the equation below
centrifugal force = frictional force
m x r x ω^{2} = Uk x m x g
r x ω^{2} = Uk x g
Uk = 
where ω (angular velocity) = 
=
= 1.14
Uk =
= 0.76
Answer:
15 N
Explanation:
According to Newton's third law of motion, to every action, there is an equal and opposite reaction. This reaction is equal in magnitude to the force acting but in an opposite direction.
Now, if the book weighs 15 N, an opposite equal force will be: N = -15 N
But the magnitude of this will be the absolute value which is 15N.
If the length and linear density are constant, the frequency is directly proportional to the square root of the tension.