When liquid cools, both its density and volume increases. Therefore the answer to your question are #s 1 and 5. This is due to the fact that molecules which are compacted or pressed against each other form a solid, and when they start to cool-down the molecules start to break free from each other increasing the density of a liquid and the space that it occupies.
<span>We know the change of thermal energy is proportional to the specific heat of the matter, its mass and the change of temperatures, according the following formula:
Q = C*m*(Tf-Ti)
where:
Q is the heat added or removed (in joules, J)
C is the specific heat of the matter, in our case air 1,000 J/(Kg*C)
m is the mass, in our case 50 kg of air
Tf is final temperature
Ti is initial temperature
then:
Q = 1000 * 50 * (30-20) = 500,000 Joules
That means that 500,000 joules need to be added to increase temperature of the room 10 ÂşC (from 20 to 30 ÂşC)</span>
Hello!
Answer:
2000 J
Explanation
Work equation is expressed as:

Where:
F: Applied force
d: traveled distance
α: Angle between the direction of the force and the direction of the movement. (in this case, both of the direction are the same, so the angle is 0°)
By substituting:

Have a nice day!
Answer:
is the minimum depth of snow for survivable stopping.
Explanation:
Given:
- terminal velocity of fall,

- mass of the paratrooper,

- force on the paratrooper by the ice to stop him,

<u>Firstly, we calculate the deceleration caused in the snow:</u>



Now, using equation of motion:
....................(1)
where:
v = final velocity of the body after stopping
u = initial velocity of the body just before hitting the snow
a = acceleration of the body in the snow
s = distance through in the snow
Putting respective values in eq. (1)

