Answer:
2.5 * 10^12 Nm-2
Explanation:
Stretching force = 20 * 10^3 N
diameter = 10 * 10^-3 m
extension = 0.2 * 10^-3 m
length of bar = 2m
Young Modulus = stress/strain
stress = Force/Area
Strain = extension/length
Young Modulus = Force/Area/extension/length
But area = πr^2 = 3.142 * (5 *10^-3)^2 = 7.9 * 10^-5 m^2
Stress = 20 * 10^3/7.9 * 10^-5 = 2.5 * 10^8 Nm-2
Strain = 0.2 * 10^-3/2 = 1 * 10^-4
Young Modulus = 2.5 * 10^8/1 * 10^-4
Young Modulus = 2.5 * 10^12 Nm-2
