I think the logical question here is to either find the distance or the displacement. They differ in such a way that distance is a scalar quantity that does not focus on the direction. Displacement is a vector quantity that covers the distance from the starting point to end point. Because it travels only in one direction (to the east), in this condition, distance is equal to displacement.
Distance = Displacement = 3,000 m + 1,500 m = 4,500 m
Water was confirmed to be on the sunlit surface of the Moon
Answer: Neon is a colorless gas at room temperature: Physical property
At room temperature, mercury is a liquid: Physical property
Apple slices turn brown when exposed to air: Chemical property
Phosphorus will ignite when exposed to air: Chemical property
Explanation:
Physical property is defined as the property of a substance which becomes evident during physical change in which there is alteration in shape, size etc. No new substance gets formed during physical change.
Example: Neon is a colorless gas at room temperature
At room temperature, mercury is a liquid.
Chemical property is defined as the property of a substance which becomes evident during chemical change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Apple slices turn brown when exposed to air: It undergoes oxidation which is a chemical change
Phosphorus will ignite when exposed to air: It undergoes oxidation which is a chemical change
Answer:
(B) Dark energy does not exist and there is much more matter than current evidence suggests.
Explanation:
The repulsive force which is accelerating expansion of the universe is called as dark energy. Most of matter present in the universe is the dark matter of about eighty five percent.
So, a collapsing universe would not have the dark energy and there is more matter which is not the dark matter. This theory is rejected because expansion of the universe is observable.
