"In a pure substance all the particles must be identical; therefore pure substances are composed only of elements." Do you agree
1 answer:
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Answer:
It must be 4 times high.
Explanation:
- Assuming that the car can be treated as a point mass, and that the ramp is frictionless, the total mechanical energy must be conserved.
- This means, that at any time, the following must be true:
- ΔK (change in kinetic energy) = ΔU (change in gravitational potential energy)
⇒
- Let's call v₁, to the final speed of the car, and h₁ to the height of the ramp.
So, at the bottom of the ramp, all the gravitational potential energy
must be equal to the kinetic energy of the car (Defining the bottom of
the ramp as our zero reference for the gravitational potential energy):
(1)
- Now, let's do v₂ = 2* v₁
- Replacing in (1) we get:
(2)
- Dividing (2) by (1), and rearranging terms, we get:
- h₂ = 4* h₁
The wavelength of the note is 
. Since the speed of the wave is the speed of sound, 
, the frequency of the note is
Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
where
is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by
where
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L: