Answer: Melting
Explanation:
When Frieda made a pyramid of marshmallows, she was representing the atoms in a solid substance as the atoms are clumped together and unable to move.
When she then knocks it down, she is showing the movement of atoms in a liquid substance as they are now freer than they were before. The process by which substances go from solid to liquid is melting.
Answer:
P = 10 kPa
Explanation:
Given that,
The mass of a small table, m = 4 kg
The area of each leg = 0.001 m²
We need to find the pressure exerted by the table on the floor. Pressure is equal to the force per unit area. So

So, the required pressure is 10 kPa.
Answer:
Turn the heater on
Explanation:
There are two main forces involved in a balloon flight
The downward force is the total weight of the balloon: the air it contains, the gas bag, the basket, the passengers, etc.
The upward force is the weight of the of the air the balloon displaces.
During level flight
,
buoyant force = weight of displaced air - total weight of balloon
If you increase the temperature of the air in the bag, the air molecules spread out and leave through the bottom of the bag.
The balloon still has the same volume, so the weight of displaced outside air stays the same.
However, the balloon has lost some hot inside air, so its total weight decreases.
The upward force is greater than the downward force, so the balloon rises.
The potential energy decreases while the kinetic energy increases.