If you've ever mixed water and oil together,you've probably noticed that the oil rises to the top and the water stays at the bottom-- no matter how much you try to shake them. This is because oil is less dense than water, making it float to the top. The molecules in oil are larger than those in water, so they don't pack as tightly together as they do in water. In a mixture of oil and vinegar, the<span> </span>oil <span>floats on the </span>vinegar/<span>water mixture, while the solids sink to the bottom. So, if one material floats over another, the material on top is less dense.
Let me know if this helps! :)</span>
It’s gonna be Oxygen ....
A) 
The total energy of the system is equal to the maximum elastic potential energy, that is achieved when the displacement is equal to the amplitude (x=A):
(1)
where k is the spring constant.
The total energy, which is conserved, at any other point of the motion is the sum of elastic potential energy and kinetic energy:
(2)
where x is the displacement, m the mass, and v the speed.
We want to know the displacement x at which the elastic potential energy is 1/3 of the kinetic energy:
Using (2) we can rewrite this as
And using (1), we find
Substituting 
into the last equation, we find the value of x:
B) 
In this case, the kinetic energy is 1/10 of the total energy:
Since we have
we can write
And so we find:
Answer:
(C) greater than zero but less than 45° above the horizontal
Explanation:
The range of a projectile is given by R = v²sin2θ/g.
For maximum range, sin2θ = 1 ⇒ 2θ = sin⁻¹(1) = 90°
2θ = 90°
θ = 90°/2 = 45°
So the maximum horizontal distance R is in the range 0 < θ < 45°, if θ is the angle above the horizontal.
We Know, Power = Energy/Time
Substitute the known value. which is P = 350 watt, & T = 30 sec
350 = E/30
E = 350 * 30
E = 1050 Joules.
So, your answer is 1050 Joules.
Hope this helps! Keep studying!
