Explanation : Tina is doing work all of the time because whiles she’s pulling and allowing the rope to be pulled her body using muscles to keep herself upright and a firm grip on the rope.
The correct answer is B. hopes this help
Explanation:
It is given that,
Mass of concrete pilling, m = 50 kg
Diameter of wire, d = 1 mm
Radius of wire, r = 0.0005 m
Length of wire, L = 11.2
Young modulus of steel, 
The young modulus of a wire is given by :





So, the wire will stretch 0.034 meters. Hence, this is the required solution.
Answer:

Explanation:
Since the formula for kinetic energy of an object is:

Where m is the mass of the object and v is the speed. We can substitute m =
kg and v = 17900m/s:
