1 and A
2 and B
3 and D
4 and C
Answer:
.
Assumptions:
- The object is dropped in a free fall.
- There's no air resistance.
- The downward acceleration due to gravity is
Explanation:
Consider the "SUVAT" equation
,
where
- is the final velocity,
- is the initial velocity,
- is the acceleration of the object, and
- is the change in the object's position.
For example, if the bottle needs to achieve a speed of by the time it reaches the ground,
- since the statement that the bottle is "dropped" implies a free fall.
- .
Apply the previous equation to find the minimum height, :
.
Replace the value and apply the formula to find the minimum height required to reach different final speeds.
Answer;
It does not have an hypothesis
Explanation;
The goal of descriptive investigation is to describe. It should provide factual, accurate and systematic descriptions of phenomena without attempting to infer causal relationships. It does not answer questions about the how, when, or why a particular phenomenon occurred.
A descriptive investigation includes a question but no hypothesis. Observations are recorded, but no comparisons are made and no variables are manipulated.
The total energy of the system is always conserve, therefore at all the point A, B & C the total energy of the skater is same.
Kinetic energy is directly proportional to the velocity, as the skater reaches the top of the pipe, the velocity of the skater would be zero, so there would be no kinetic energy, as he progress down the pipe the velocity of the skater increases, thus kinetic energy increase and highest at the bottom of the pipe, therefore the increasing order of the kinetic energy is C>B>A.
Potential energy is dependent on the height, as the height increases potential energy will also increase. therefore the increasing order of the potential energy is A>B>C.
Force = mass • acceleration
1) Find acceleration
-) 8kg ball
a= v/t
a= .2/ 10 = .02 m/s^2
Force = 8kg • .02 = .16N
-) 4kg ball
a= v/t
a= 1.0/ 10 = .1 m/s^2
Force = 4kg • .1 = .4N
Answer: The 8kg ball would need more force because it requires .16N, while the 4kg only need .4N .