I) You walk barefoot on the hot street and it burns your toes.
The road is in direct contact with your skin. Thermal energy from the road will transfer to the bottom of your feet, then to the rest of your body. This is an example of conduction.
II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.
Just like in the previous example, the hot leather is in direct contact with your skin (I guess if you're going to drive naked). Thermal energy from the leather will transfe to your skin, then to the rest of your body. This is also conduction.
III) A flame heats the air inside a hot air balloon and the balloon rises.
The flame heats air directly at the bottom of the balloon. The warm air expands and becomes less dense. This will rise and let the unheated, denser air in the balloon fall down toward the flame. This is an example of the convection cycle.
IV) A boy sits to the side of a campfire. He is 10 feet away, but still feels warm.
The campfire heats air directly nearby. The warm air expands and moves away from the fire in all directions, leaving behind unheated, denser air to be heated up. Some of the warm air reaches the boy. This is another example of convection.
The answer is A) 1 and 2.
Answer:
<h3>The answer is option B</h3>
Explanation:
The frequency of a wave can be found by using the formula
where
c is the velocity
From the question
wavelength = 0.39 m
c = 86 m/s
We have
We have the final answer as
<h3>200 Hz</h3>
Hope this helps you
Answer:
(B) the sum total of all matter and energy
Explanation:
Universe comprises of all the matter and energy that exists in space. It contains billions of stars, planets and interstellar matter that is clouds of dust and gas. There is large amount of the empty space in between.
Universe contains stars as many as grains of sand on all beaches on the Earth. These stars are grouped into galaxies. Milky Way is one of the galaxies. Galaxies can be grouped into clusters and super-clusters.
The three phases of matter differ in properties just because of the proximity of their molecules. The solid phase is the most organized of all. Its atoms are compactly arranged together and has the strongest intermolecular forces to keep them together. This is why they have a definite shape and volume. The liquid phase have molecules that are far away from each other, but not as far as that of the gas phase. The liquid and gas phases can be lumped into one group called fluids because they have the same property - they take the shape and volume of their container.
To make an analogy, see the attached picture for your reference.
Answer:
It would be a physical change because you aren't changing to chemical properties of the glass, just the shape.
