Ablock weighing 3.7 kg is suspended from the ceiling of a truck trailer by a hanging bungee cord. the cord has a cross-sectional area 40 mm2 and an unstretched length of 43 cm.
the truck begins stopped at a red light on a state highway. while stopped, the block hangs straight down to a distance 53 cm below the hook that attaches the bungee cord to the ceiling of the truck.

(a) what is the young's modulus of the cord?

Explanation:

Natural length of the string is given as

length of the string while block is hanging on it

extension in length is given as

now we have strain in the string is given as

similarly we will have cross-sectional area of the string is given as

now the stress in the string is given as

Now Young's Modulus is given as

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

c) up is the direction the magnetic force is acting on the charge.