Answer:
0.144 kg of water
Explanation:
From Raoult's law,
Mole fraction of solvent = vapor pressure of solution ÷ vapor pressure of solvent = 423 mmHg ÷ 528.8 mmHg = 0.8
Let the moles of solvent (water) be y
Moles of solute (C3H8O3) = 2 mole
Total moles of solution = moles of solvent + moles of solute = (y + 2) mol
Mole fraction of solvent = moles of solvent/total moles of solution
0.8 = y/(y + 2)
y = 0.8(y + 2)
y = 0.8y + 1.6
y - 0.8y = 1.6
0.2y = 1.6
y = 1.6/0.2 = 8
Moles of solvent (water) = 8 mol
Mass of water = moles of water × MW = 8 mol × 18 g/mol = 144 g = 144/1000 = 0.144 kg
I assume L=120 yards as the length of the football field.
1) The average speed is given by the total distance covered by the player divided by the time taken.
The total distance covered to go from one goal line to the other and then back to the 40-yards line is

And the time taken is t=22.4 s, so the average speed of the player is

2) The find the average velocity, we should also consider the direction (and the sign) of the velocity.
In the the first part of the motion, the player goes from one goal line to the other one, so he covers 120 y. However, in the second part of the motion he goes back by 80 y. Therefore, the net displacement of the player is

and so, the average velocity is
Answer:
5..No work is being done.
Explanation:
Hello!
Remember that the concept of work is defined as the force required to move a certain body distance, it is calculated as the product of force by distance.
therefore, the work required to raise the box is 150J.
However, the work required to keep the box lifted without moving is zero since although the box has a force due to the weight it does not move.
Explanation:
Newton's law of universal gravitation states that every object attracts every other object with a force. For any two objects, this force is directly proportional to the mass of each object. The greater the masses, the greater the force of attraction between them. Newton also deduced that this force decreases as the square of the distance between the centers of the objects increases. The farther away the objects are from each other, the less the force of attraction between them.
Calculate the number of neutrons. Now you know that atomic number = number of protons, and mass number = number of protons + number of neutrons. To find the number of neutrons in an element, subtract the atomic number from the mass number.