Answer:

Explanation:
The potential energy of the spring or the work done by the spring is given by :
............(1)
k is the spring constant
d is the compression
When the spring is compressed a distance d' = d/3, let W' is the work is required to load the second dart. Then the work done is given by :

.............(2)
Dividing equation (1) and (2) :



So, the work required to load the second dart compared to that required to load the first is one-Ninth as much. Therefore, the correct option is (E).
Answer:
The correct option is b) In galaxy clusters
Explanation:
A type of galaxy that appear elliptical in shape and have an almost featureless and smooth image is known as the elliptical galaxy.
An elliptical galaxy is three dimensional and consists of more than one hundred trillion stars which are present in random orbits around the centre.
Elliptical galaxy is generally found in the galaxy clusters.
Answer:
0.124 m
Explanation:
the period of a simple pendulum with a small amplitude is given as
T = 2π [√(I/mgd)]
From the above stated formula,
I = moment of inertia
m = mass of the pendulum
g = acceleration due to gravity, 9.8 m/s²
d = distance from rotation axis due to center of gravity
Also, moment of Inertia, I = 2mr², if we substitute this in the above formula, we have
T = 2π [√(2mr²/mgd)]
If we assume that our r = d, then we have
T = 2π [√(2r/g)]
If we make r the subject of the formula in the above equation, we get
r = gT² / 8π²
r = (9.8 * 1²) / 8 * π²
r = 9.8 / 78.98
r = 0.124 m
Thus, the radius of the hoop is 0.124 m
Momentum is (mass) times (speed), so nothing that is at rest has any momentum. If the battleship is at rest, then a mosquito in flight, a leaf falling from a tree, and your speedy baseball each have more momentum than the ship has.