Answer:
114.44 J
Explanation:
From Hook's Law,
F = ke................. Equation 1
Where F = Force required to stretch the spring, k = spring constant, e = extension.
make k the subject of the equation
k = F/e.............. Equation 2
Given: F = 10 lb = (10×4.45) N = 44.5 N, e = 4 in = (4×0.254) = 1.016 m.
Substitute into equation 2
k = 44.5/1.016
k = 43.799 N/m
Work done in stretching the 9 in beyond its natural length
W = 1/2ke²................. Equation 3
Given: e = 9 in = (9×0.254) = 2.286 m, k = 43.799 N/m
Substitute into equation 3
W = 1/2×43.799×2.286²
W = 114.44 J
Answer: is A
The acceleration of an object is determined by its mass and the net force acting on it.
Newton's second law says that "F=ma". what this means is that the force you apply to an object is equal to its mass times how fast it is accelerating.
Hope it helped.
W = F * s
Here, F = 50 N
s = 15 m
Substitute their values,
W = 50 * 15
W = 750 J
In short, Your Answer would be 750 Joules
Hope this helps!