Answer:
(a). The spring compressed is 
.
(b). The acceleration is 1.5 g.
Explanation:
Given that,
Acceleration = a
mass = m
spring constant = k
(a). We need to calculate the spring compressed
Using balance equation
....(I)
The spring compressed is .
(b). If the compression is 2.5 times larger than it is when the mass sits in a still elevator,
The compression is given by
Here, acceleration is zero
So, 
We need to calculate the acceleration
Put the value of x in equation (I)
Hence, (a). The spring compressed is .
(b). The acceleration is 1.5 g.
120n
since the speed is doubled, her force is doubled
<h2>Answer: decibels
</h2>
The decibel 
is the relation between two values: the pressure produced by a sound wave and a pressure taken as a reference. Resulting in a dimensionless value.
It should be noted that itself<u> is not a unit of measure</u>, since in reality the unit is bel 
(which <u>is not part of the International System of Units</u>) in honor of Alexander Graham Bell.
However, given the amplitude of the measured elements in practice, its submultiple, the decibel, is used. That is, this quotient is a logarithmic expression, where 
Answer:
b) 338 N
Explanation: let m be the mass of the gymnast and a be the acceleration of the gymnast.
the force required to accelerate the gymnast is given by:
F = m×a
= (45.0)×(7.50)
= 337.5 N
Therefore, the force a trampoline has to apply is 138 N.
