ANSWER
EXPLANATION
First, let us make a sketch of the question:
From the diagram:
=> black line represents North
=> green line represents East
=> blue line represents West
=> red line represents South
From the diagram, we see that at the end of his journey, he returns to his start point.
Since displacement is the measure of the change in the position of an object and the boy's position did not change after the journey, his displacement is:
12N because you are just adding those two up on the same side
Answer:
(a) 0.2618 J
(b) 0.1558 J
(c) 0 J
Explanation:
from Hook's Law,
The energy stored in a stretched spring = 1/2ke²
Ep = 1/2ke² ......................... Equation 1
Where k = spring constant, e = extension, E p = potential energy stored in the spring.
(a) When The spring is stretched to 4.11 cm,
Given: k = 310 N/m, e = 4.11 cm = 0.0411 m
Substituting these values into equation 1
Ep = 1/2(310)(0.0411)²
Ep = 155(0.0016892)
Ep =155×0.0016892
Ep = 0.2618 J.
(b) When the spring is stretched 3.17 cm
e = 3.17 cm = 0.0317 m.
Ep = 1/2(310)(0.0317)²
Ep = 155(0.0317)²
Ep = 155(0.0010049)
Ep = 0.155758 J
Ep ≈ 0.1558 J.
(c) When the spring is unstretched,
e = 0 m, k = 310 N/m
Ep = 1/2(310)(0)²
Ep = 0 J.
