<u>Answer:</u> The elevation in boiling point is 1.024°C.
<u>Explanation:</u>
To calculate the elevation in boiling point, we use the equation:

where,
i = Van't Hoff factor = 2 (for NaCl)
= change in boiling point = ?
= boiling point constant = 
m = molality = 1.0 m
Putting values in above equation, we get:

Hence, the elevation in boiling point is 1.024°C.
This is called average speed.Its really simple
Answer:
200 N
Explanation:
Given that,
A ball traveling at 15 m/s hits a bat with a force of 200 N.
We need to find the force that the bat moving at 20 m/s hit the ball with.
We know that, this probelm is based on Newton's third law of motion. The force that the ball exerting on bat should be equal to the force that the bat exerting in the ball but in opposite direction.
It would mean that the ball hits the ball with a force of 200 N. Hence, the correct option is (a).