Answer:
For any material if ∈ is the axial strain then the lateral strain is given by -μ∈ is the lateral strain in the object
Where,
μ is the poisson's ratio of the material
The longitudinal strain is calculated as follows

Thus the lateral strain becomes

now by definition of lateral strain we have

By hookes law the stress developed due to the given strain is given by

Applying values we get

Thus the force is calculated as

Complete Question
The cars of a roller-coaster ride have a speed of 19.0 km/h as they pass over the top of the circular track. Neglect any friction and calculate their speed v when they reach the horizontal bottom position. At the top position, the radius of the circular path of their mass centers is 21 m, and all six cars have the same mass.V = -18 m What is v?X km/h
Answer:

Explanation:
Velocity 
Radius 
initial velocity u
Generally the equation for Angle is mathematically given by




Generally
Height of mass



Generally the equation for Work Energy is mathematically given by

Therefore


