In an experiment to determine the acceleration due to gravity, one student holds a pencil at arm’s length and drops it. another student starts a timer when the first student lets go and stops the timer when the pencil hits the ground. they repeat this several times and take an average. is this a valid experiment, why or why not?

a. no, it is not valid because they are only dropping one item.
b. no, it is not valid because taking the average will increase rounding error.
c. yes it is valid.
d. no, it is not valid because the short distance means there will be a lot of error due to the student’s reaction time.

I think it is not a valid experiment . I go with D

answer: option (4) is the correct answer.

explanation:

areas which are at low altitudes and near the equator tend to receive direct sunlight from the sun. hence, heat energy or radiations from the sun make these areas warmer and they have warmest water.

whereas areas which are at high altitudes and away from the equator do no receive direct sunlight. hence, no direct contact from the sun makes these regions colder and thus, they have colder water.

thus, we can conclude that the statement areas at low latitudes near the equator have the warmest water because they receive the most direct sunlight best explains the relationship between an area's geography and the temperature of its surface water.

hloride, what is the mass of calcium in

explanation: