The correct answer to the question is : B) The weight of the water, and C) The height of the water.
EXPLANATION :
Before coming into any conclusion, first we have to understand potential energy of a body.
The potential energy of a body due to its position from ground is known as gravitational potential energy.
The gravitational potential energy is calculated as -
Potential energy P.E = mgh
Here, m is the mass of the body, and g is the acceleration due to gravity.
h stands for the height of the body from the ground.
We know that weight of a body is equal to the product of mass with acceleration due to gravity.
Hence, weight W = mg
Hence, potential energy is written as P.E = weight × height.
Hence, potential energy depends on the weight and height of the water.
Ok, so adopting that the 2nd satellite is at rest and that we're not moving anywhere near the speed of light (so no special relativity considerations), we can just add the two speed together, and say the 1st satellite is moving at 0.9m/s at the 2nd satellite. We can then set up our conservation of momentum equation, m₁v₁+m₂v₂ = m₁v₃+m₂v₄, where I'm calling v 1 and 2 the initial velocities of satellite 1 and 2 and v 3 and 4 the final velocities of satellite 1 and 2 respectively. We know, based on our chosen frame, that v₂ = 0, so that falls out to leave m₁v₁ = m₁v₃+m₂v₄, but we don't know v₃ or v₄, so we need another equation. Let's set up conversation of energy (elastic collisions conserve energy), where we only have to worry about kinetic energy (K = 1/2mv²) for each satellite before and after the collision. So we get 1/2m₁v₁²+1/2m₂v₂² = 1/2m₁v₃²+1/2m₂v₄². Now we have 2 equations and two unknown variables so let's solve with substitution. Let's solve the momentum equation for v₃, v₃ = (m₁v₁ - m₂v₄)/m₁, sub that into the energy equation, cancel the 1/2's and let's drop the v₂ terms since it's zero and we get: m₁v₁² = m₁((m₁v₁ - m₂v₄)/m₁)²+m₂v₄², then after some algebra we get v₄ = sqrt(m₁v₁/((v₁ - m₂/m₁)²+m₂)), then we plug in numbers v₄ = sqrt((4.5*10³*0.9/((0.9-(7.5/4.5))²+7.5*10³) = 0.73 m/s for the 2nd satellite after the collision. Then go back to v₃ = (m₁v₁ - m₂v₄)/m₁ and plug in numbers now that we know v₄ and we get v₃ = (4.5*10³*0.9 - 7.5*10³*0.73)/(4.5*10³) = -0.3167 m/s for the 1st satellite.
It goes through the holes in the cup .
‘velocity’ refers to how fast an object is moving ‘in a particular direction’. speed is only how fast something is moving and velocity is how fast something is moving AND the direction. (hope this helps)
