Answer:
The tensile stress on the wire is 550 MPa.
Explanation:
Given;
Radius of copper wire, R = 3.5 mm
extension of the copper wire, e = 5.0×10⁻³ L
L is the original length of the copper wire,
Young's modulus for copper, Y = 11×10¹⁰Pa.
Young's modulus, Y is given as the ratio of tensile stress to tensile strain, measured in the same unit as Young's modulus.
Therefore, the tensile stress on the wire is 550 MPa.
Answer:
skid distance = 180 m
Explanation:
given,
mass of the car = 1000 Kg
speed of the car = 40 Km/hr
distance to stop = 20 m
if speed is now = 120 Km/he
distance to stop = ?
from given question we can state that,
Work done by the friction is equal to the change in kinetic energy of the car.
............(1)
And we also know that work is directly proportional to displacement
W = F × x...........................(2)
from the equation (1) and (2)
x ∝ v²
now,
here velocity is increased from 40 km/h to 120 km/h means velocity is increase 3 times
so displacement will be equal to 3² or 9 times
hence, skid distance will be equal to 9 x 20 = 180 m
skid distance = 180 m