A) According to the nebular theory, the Solar System formed from a huge gaseous nebula which at a certain point was perturbated. Atoms and molecules started colliding, forming planetesimals (a sort of big rocks). The planetesimals were attracted to each other by gravity, forming bigger warm almost spherical objects called protoplanets, which at the end cooled down forming planets.
Therefore the correct answer is "all of the above".
b) The planets closer to the Sun were (and still are) subject to higher temperatures, due to their close distance to the Sun. In these conditions, rocky materials undergo condensation, while iced gaseous materials undergo vaporization. In the outer parts of the Solar System temperatures are too low to allow these transformations.
The correct answer is again "all of the above".
Answer:
1.61 second
Explanation:
Angle of projection, θ = 53°
maximum height, H = 7.8 m
Let T be the time taken by the ball to travel into air. It is called time of flight.
Let u be the velocity of projection.
The formula for maximum height is given by

By substituting the values, we get

u = 9.88 m/s
Use the formula for time of flight


T = 1.61 second
Answer:
(a) 0 (b) 
Explanation:
Given that,
Mass of a supertanker, 
The engine of a generate a forward thrust of, 
(a) As the supertanker is moving with a constant velocity. We need to find the magnitude of the resistive force exerted on the tanker by the water. It is given by :
F = ma, a is the acceleration
For constant velocity, a = 0
So, F = 0
(b) The magnitude of the upward buoyant force exerted on the tanker by the water is equal to the weight of the ship.
F = mg

Hence, this is the required solution.
Answer:
Here, 5% of energy wasted as a heat lost or work done against frictional forces.
Explanation:
No engine has yet made that can convert its all input energy into mechanical energy. Some of the input energy goes in vain in the form of heat and friction.
Answer: 3
Explanation:
Lithium always has 3 protons bc it’s atomic number is 3 which is determined by its amount of protons.