Answer:
There is some sort of "rollers" on the trail part that is used to make the roller coaster move when it is going up. Then because of that, the speed gets quicker when it drops down, so then it could move for a longer time until it reaches the next arch.
Explanation:
hope this helps :)
Light travels in a straight line because it doesn't usually interact with its medium. When it does it is called refraction.
Answer:

Explanation:
From the question we are told that:
Mass 
Length 
Linear density 
Generally the equation for Frequency is mathematically given by



(This is from experience so sorry if it's wrong but) When wind instruments are played, sometimes the notes go flat or sharp depending on the speed the player blows air into the instrument as well as the warmth of the air. When playing a string instrument, the pitch can be changed in many ways. For example, when the player places their fingers on the string depending on which part of the tip of the finger you use, the tone of the sound and sometimes the pitch, changes. Looking at the question in a different way, you can change the pitch and the range of notes you can reach on the instrument (both wind and string) by changing the note you tune your instrument to. Hope this helps!!
Impulse, Δp, is the value of the change of the ball's momentum. To recall, we can express momentum, p, as the product of the object's mass and velocity. Mathematically, we have



where m is the object's mass and v is the object's velocity.
Since the ball bounced off opposite to its original direction, initial velocity and final velocity will have opposite signs. And hence, we have

Rounding the values off to three significant figures, we have Δp = 13.5 N·s.
Answer: 13.5 N·s