Consider the roller coaster car pictured [ignore air resistance and friction] a)
ID: 1265744 • Letter: C
Question
Consider the roller coaster car pictured [ignore air resistance and friction]
a) Write an algebraic expression for the total energy of the car at point B, before its release (vb=0 m/s)
b) Write an algebraic expression for the total energy of the car at point C, where y=0
c) Calculate the velocity of the car at point C.Let hB=20m, m car=400 kg
Consider the roller coaster car pictured [ignore air resistance and friction] a) Write an algebraic expression for the total energy of the car at point B, before its release (vb=0 m/s) b) Write an algebraic expression for the total energy of the car at point C, where y=0 c) Calculate the velocity of the car at point C.Let hB=20m, m car=400 kgExplanation / Answer
Solution:
a) The total energy of the car at the point B = potential energy + kinetic energy
Potential energy at the point B which is at a height hB = mghB =mass x gravity x height of point B
Kinetic energy at the point B =1/2mvb^2=0 since vb = 0
Therefore , total energy at the point B= mghB
b) Since point C is at the height y=0, its potential energy =0
The total energy at the point C= kinetic energy at C= 1/2mvC2
c) From the conservation of energy ,
The total energy of the car at C =Total energy of the car at B
=> 1/2mvC2 = mghB
=> vC = squareroot (2ghB)
=2 x 9.8 x 20
= 19.8 m/s = velocity of the car at C