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>
Answer:
A bird flies 75m in 15s.Calculate its speed
Answer:
0.9 N
Explanation:
The force exerted on an object is related to its change in momentum by:
where
F is the force exerted
is the change in momentum
is the time interval
The change in momentum can be rewritten as
where
m is the mass
u is the initial velocity
v is the final velocity
So the formula can be rewritten as
In this problem we have:
is the mass rate
is the initial velocity
is the final velocity
Therefore, the force exerted by the hail on the roof is:
<span>The answer is -0.8 m/s. We know acceleration is the average of final minus initial velocity over time (a = (vf-v0)/t). We also know that Force is equal to Mass times Acceleration (F = ma). Using our force equation, we know that the acceleration we get is negative 8.8 (-8.8). The force is acting in the opposite direction of the rugby player, hence the negative sign. From there, plug in that number for a in the velocity equation, and solve for vf, as v0 and t are known. We get 0.8 m/s in the opposite direction that the player was running.</span>
