Answer:
The water releases energy which causes the water molecules to have less kinetic and potential energy, changing their configuration from liquid to solid.
Explanation:
The conversion of water to ice is a phase change from liquid to solid. There is no chemical action taking place in this process just the state of matter taking up a new form.
- This phase change is called freezing.
- In freezing, the liquid water loses energy to the surroundings.
- By so doing, the water molecules have lesser energy
- The then take up fixed position within the lattice.
- This changes the state to solid with a well - ordered arrangement.
Answer:
A line crossing the x-axis in a velocity-time graph means that the moving object has changed its direction.
Explanation:
Velocity-Time graph:
A velocity-time graph is a two dimensional graph with velocity at its y-axis and time at its x-axis. At any point, value of y represents the velocity and value of x represents the time. The slope of the graph gives us the acceleration or deceleration of the moving object.
In a velocity-time graph:
- A straight line represents constant velocity.
- A diagonal line means that the velocity of a body is changing.
*Referring to the figure attached with the answer*
The velocity of the moving object increases at a constant rate for the first 10 minutes. Then the velocity is 60 m/min for the next 5 minutes. After that the velocity is decreasing. Till 30th minute when the velocity is at 0 m/min.
What happens here?
Velocity is a vector quantity. It has some direction. In a velocity-time graph, we are only concerned with two directions of velocity:
- Forward direction
- Backward direction
So, the object stops at 30th minute and starts moving in the reverse direction after that with an increasing velocity. <u>The point where the line cuts the x-axis is basically the point where the object starts moving in the reverse direction.</u>
Answer:

Explanation:
Let assume that gases inside bulbs behave as an ideal gas and have the same temperature. Then, conditions of gases before and after valve opened are now modelled:
Bulb A (2 L, 2 atm) - Before opening:

Bulb B (3 L, 4 atm) - Before opening:

Bulbs A & B (5 L) - After opening:

After some algebraic manipulation, a formula for final pressure is derived:

And final pressure is obtained:


Answer:
Unusually large moons form in giant impacts, which are relatively rare events
Explanation:
Solution:
- Finding large moons comparable in size to their planets result from impacts of two astro-bodies. The probability of such an event occurring is very rare.
- Even at the best luck, one moon can be made from the result of giant impact. While the probability of 6 planets having moons of comparable sizes is close to impossible. The transition from an undifferentiated cloud to a star system complete with planets and moons takes about 100 million years.
Answer:
A. demand increases and supply decreases
Explanation:
The correct answer is: The equilibrium price will rise, but equilibrium quantity may increase, decrease, or stay the same if demand increases and supply decreases