Ionic compounds typically have high melting and boiling points, and are hard and brittle. when melted or dissolved they become highly conductive, because the ions are mobilized.
Answer:
Most of UV radiation is stopped by glass & this is why you will not get sunburns behind a glass. The glass simply filters out the UV radiation that is responsible for the sunburns & protect your skins from these energetic & somewhat harmful radiation
Explanation:
Answer:
D. The motion cannot be determined without knowing the speeds of the objects before the collision.
Explanation:
This question is tricky! We know the object moving to the left has a greater mass than the one moving to the right. We'd <em>assume</em> they would move to the left because the leftwards object has a greater mass, right?
Not. So. Fast.
We can solve for the objects' final velocity using the formula for momentum, m₁v₁ + m₂v₂ = (m₁ + m₂)v .
Now here's where the trap is sprung: <em>we don't think about the equation</em>. This shows that the final velocity of the objects and the direction depends on both the mass of the objects <em>and</em> their initial velocity.
Basically, what if the 3 kg object is moving at 1 m/s and the 4 kg object is moving at –0.5 m/s? The objects would move to the <em>right</em> after the collision!
Do we know the velocity of these objects? No, right?
That means we <em>can't</em> determine the direction of their motion <u>unless we know their initial, pre-collision velocity</u>. This question is tricky because we look at the 4 kg vs. 3 kg and automatically assume the 4 kg object would dictate the direction of motion. That's not true. It depends on velocity as well.
I hope this helps you! Have a great day!
