Answer:
The ratio of kinetic energies of 5 kg object to 20 kg object is 1:1.
Explanation:
Kinetic energy is defined as energy possessed by an object due to its motion.It is calculated by:

Kinetic energy of the 5 kg object.
Mass of object,m = 5 kg
Velocity of an object = v

Kinetic energy of the 20 kg object.
Mass of object,m' = 20 kg
Velocity of an object = v'

The ratio of the kinetic energy of the 5 kilogram object to the kinetic energy of the 20-kilogram object:

Given that, v = 2v'

The ratio of kinetic energies of 5 kg object to 20 kg object is 1:1.
They measured the wavelength of light emitted by stars using spectrometers and found it was being redshifted.
This implied the stars were moving away aka the space between the scientists and the star was expanding
B. Maximal lightheadedness
Answer:
Explanation:
We shall consider direction towards left as positive Let the required velocity be v and let v makes an angle φ
Applying law of conservation of momentum along direction of original motion
m₁ v₁ - m₂ v₂ = m₂v₃ - m₁ v₄
0.132 x 1.25 - .143 x 1.14 = 1.03 cos43 x .143 - v cos θ
v cos θ = .8
Applying law of conservation of momentum along direction perpendicular to direction of original motion
1.03 sin 43 x .143 = .132 x v sinθ
v sinθ = .76
squaring and adding
v² = .76 ² + .8²
v = 1.1 m /s
Tan θ = .76 / .8
θ = 44°
A. <span>Standing is health-enhancing because it uses energy.
Because standing can burn a lot of calories.</span>