Answer:
m = 69.9 kg
Explanation:
The mass and the weight of an object are two different quantities. Mass is basically the amount of matter that is present in a body. It remains same everywhere in the universe and measured in kilograms.
Weight is basically a force. It is the force by which earth attracts everything towards itself. The weight of an object changes from planet to planet, with the change in value of the gravitational acceleration (g).
Therefore, the relation between mass and weight of an object is given by the following formula:
W = mg
m = W/g
where,
m = mass = ?
W = Weight = 685 N
g = 9.8 m/s²
Therefore,
m = (685 N)/(9.8 m/s²)
<u>m = 69.9 kg</u>
Answer:
I would say that I agree with the one that said that each hill must be lower than the previous one and use the principle of conservation of energy to explain.
Explanation:
Roller coaster are usually designed such that its total energy remains conserved at any point on the track. Now, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. At certain height on the track, the total energy of the roller coaster is in form of potential energy, which gets converted to kinetic energy as soon as it starts sliding down the hill till get to the hill's endpoint where it has maximum kinetic energy. The cycle of sliding from a high point on the track to a low point on the track means there is potential energy is converted to kinetic energy and kinetic energy then converts back to potential energy and the cycle continues.
However, due to the effect of gravity and frictional force between the track and the coaster, the energy of the coaster is gradually reduces, so it becomes a bit difficult for the coaster to move to the next hill of the same height. It is for this reason that each hill must be lower than the previous one, so that the coaster can overcome the next hill's height with its reduced energy until it loses all its energy and comes to a stop.
Potential Energy = mgh,
where m = mass in kg, g ≈ 10 m/s², h = height above ground = 8 m
PE = mgh
= 70*10*8 = 5600 J
Enough data points would have been collected when specific data for upward and downward motion are collected.
<h3>
What is a Data point?</h3>
A data point is a discrete unit of information. This information is always unique.
<h3>Free fall</h3>
An object subjected to free fall is under the influence of gravity. An object subjected has different time of motion for upward and downward motion.
Thus, we can conclude that enough data points would have been collected when specific data for upward and downward motion are collected.
Learn more about free fall here: brainly.com/question/10909077
8 meters per second. To find velocity is to divide distance by total time. so 400/50.
