In 0.750 s, a 7.00 kg block is pulled through a distance of 4.00 m on a friction
ID: 2037505 • Letter: I
Question
In 0.750 s, a 7.00 kg block is pulled through a distance of 4.00 m on a frictionless horizontal surface, starting from rest. The block has a constant acceleration and is pulled by means of a horizontal spring that is attached to the block. The spring constant of the spring is 415 n/m. By how much does the spring stretch? In 0.750 s, a 7.00 kg block is pulled through a distance of 4.00 m on a frictionless horizontal surface, starting from rest. The block has a constant acceleration and is pulled by means of a horizontal spring that is attached to the block. The spring constant of the spring is 415 n/m. By how much does the spring stretch?Explanation / Answer
Given,
t = 0.75 m
d = 4 m
m = 7 kg
k = 415 N/m
So,
let a is the acceleration of the block
d = vo*t + 0.5*a*t^2
d = 0 + 0.5*a*t^2
a = 2*d/t^2
= 2*4/0.75^2
= 14.22 m/s^2
So,
Force exerted by the spring,
= F = m*a
= 14.22*7
= 99.54 N
Then,
From Hook's law,
extension of the spring,
= x= F/K
= 99.54/415
= 0.239 m