Answer:
Explanation:
Change in length of spring = 2.13 m
Component of weight acting on spring = mg sinθ
so
mg sinθ = k x where k is spring constant and x is total stretch due to force on the spring.
Here x = 2.13
mg sin17 = k x 2.13
31 x 9.8 sin17 = k x 2.13
k = 41.7 N/m
b ) In case surface had friction , spring would have stretched by less distance .
It is so because , the work done by gravity in stretching down is stored as potential energy in spring . In case of dissipative force like friction , it also takes up some energy in the form of heat etc so spring stretches less.
One of Kepler's laws is that the orbits of planets are elliptical. It's not a suggestion.
BTW, circles are ellipses too, but so special that their likelihood is close to zero.
A technique in which the muscles are stretched by an outside force is called Passive Stretching
Option (D) is the correct one.
In order to increase the amount of work done, we need to increase the force applied to the object.
Explanation:
Let's say right is positive and left is negative.
F₁ = -150 N
F₂ = 220 N
Fnet = F₁ + F₂
Fnet = -150 N + 220 N
Fnet = 70 N
The magnitude of Fnet is 70 N, and since it's positive, the direction is to the right.
And since Fnet isn't 0, the force is unbalanced and the motion is changing.
