A. Balloons can be filled with air.
C. Air has mass.
That's the 'electrostatic' force.
Given that,
Initial velocity , Vi = 0
Final velocity , Vf = 40 m/s
Acceleration due to gravity , a = 9.81 m/s²
Distance can be calculated as,
2as = Vf² - Vi²
2 * 9.81 *s = 40² - 0²
s = 81.55 m
For half height, that is, s = 40.77m
Vf= ??
2as = Vf² - Vi²
2 * 9.81 * 40.77 = Vf² - 0²
Vf² = 800
Vf = 28.28 m/s
Therefore, speed of roller coaster when height is half of its starting point will be 28 m/s.
An action-reaction pair would be a pair in which one of the elements exerts a force on the other element (action), and then the other element would respond to this force by exerting another force in the opposite direction (reaction).
From the given choices, we will see that:
For choice A, the moon exerts a force on the earth by pulling it (action) and the earth responds to this force by pulling the moon (reaction in opposite direction of the action).
Therefore, the correct choice would be:
A. <span>The Moon Pulls on Earth, and Earth pulls back on the moon.</span>
Well depending on what current the heater pulls im going to assume about 13, and 13A for the hair dryer, thats 26A on the 40A circuit.
I dont see how a lightbulb could overload the circuit.
Anyway, assuming the circuit is overloaded by some really big heater- the circuit would trip, the fuse would go and remain off. Most houses are fitted with seperate circuits for lights and sockets, so the light may remain on depending on the breaker board. - the reason for them all being able to run with the sudden overload may be due to a surge.
One solution to this is not to put such a large heater on the circuit with other appliances.
Another may be to dry your hair in the dark