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:
Not between significant digits.
Explanation:
A zero not significant when it's not between significant digits.
Answer:
Heat
Explanation:
Energy that is transferred from a warmer object to a cooler object is called heat.
Answer:
0.2
Explanation:
The given parameters are;
The acceleration of the train, a = 0.2·g
The mass of the person standing on the train = m
Let μ represent the coefficient of static friction, we have;
The force acting on the person, F = m × a = m × 0.2·g
The force of friction acting between the feet and the floor,
= m·g·μ
For the person not to slide we have;
The force acting on the person = The force of friction acting between the feet and the floor
F = 
∴ m × 0.2·g = m·g·μ
From which we get;
0.2 = μ
The coefficient of static friction that must exist between the feet and the floor if the person is not to slide, μ = 0.2.
Explanation:
Velocity = displacement / time
v = √((58 m)² + (135 m)²) / (12 min × 60 s/min)
v = 0.20 m/s