C. This is the idea of "black body radiation". Charcoal/carbon is a "perfect black body". Absorbs all radiation. There's a whole host of stuff about this in physics, including, I think, Planck's (Nobel Prize winner) black body radiation theory.
Answer:
B).315mph
Explanation:
Let the speed of the plane = p
Let the speed of the wind = w
Set up the system equation as;
Relative V: Time: Distance:
in wind direction: p + w 2 700
against wind: p - w 2.5 700
2(p + w) = 700
2.5(p - w) = 700
2p + 2w = 700
2.5p - 2.5w = 700
2.5 x: 5p + 5w = 1750
2 x: 5p - 5w = 1400
10p = 3150
p = 315 mph
Therefore, he speed of the plane in still air is 315 mph
Conservation of momentum requires that the sum of momenta after is equal to that before. Since initially nothing is moving, the sum after the shot will also add to zero.
m₁v₁ = -m₂v₂
Solve for the cannon's velocity v₁
v₁ = -m₂v₂/m₁ = -2.10m/s
The negative sign means it's moving 2.10m/s south.
I would say a short person with muscles considering they are closer to the ground, but they may not be able to build up as much force in such a short time compared to the tall person.
<u>The following statements are false about collisions:
</u>
- The velocity change of two respective objects involved in a collision will always be equal.
- Total momentum is always conserved between any two objects involved in a collision.
Answer: Option B, and D
<u>Explanation:
</u>
In any collisions, equal amount of net force will be acted upon the colliding objects due to the third law of Newton, irrespective of the significance difference in mass of the objects. Similarly, they can also have different acceleration values during collision of two objects if the masses are identical.
But the statements regarding the equal change in velocity of two objects respectively involved in collision always is false, as the conservation of momentum is applicable for isolated system only. So it is true for only isolated system and not in all the systems.
The same reason goes for falsifying the fourth statement which states that total momentum is always conserved between two objects involved in a collision as this statement is only true for isolated system where the conservation of momentum can be applied. Thus the second and fourth statement is false regarding collision.
