Your answer is: theres not a certain age. its when the person decides to act mature.
Hope i helped!:)
As science being dynamic many things will change and due to this changes many things and theories will be new to us. the model of the atom is not weak, it is just developing as time progress because in the early times it is not fully understood because of the lack of technology to study, what scientist do is just filling the knowledge gap of the previous studies.
The period of the musical note is 
seconds.
Answer: Option A
<u>Explanation:</u>
The frequency is defined as the number of oscillations or a complete cycle of wave occurred in a given time interval. So the frequency is inversely proportional to the time period. Thus the mathematical representation of frequency with time period is
As the frequency is given as 
, the time period can be found as
Thus,
Thus the time period for the frequency of the musical note is seconds.
Answer: Explanation:
She can measure the volume and mass of the marble, the volume and mass of the water, and the volume and mass of the graduated cylinder. She can measure the volume and mass of the marble, the volume and mass of the water, and the mass of the graduated cylinder.
Answer:
0.82 m/s
Explanation:
From the law of conservation of momentum,
Total momentum = Final momentum.
mu+m'u' = V(m+m')......................... equation 1
Where m = mass of Lillian, u = initial velocity of Lillian before she catches the dog, m' = mass of the dog, u' = initial velocity of the dog, V = velocity of Lillian and the dog.
make V the subject of the equation,
V = (mu+m'u')/(m+m')................ Equation 2
Given: m = 40 kg, m' = 15 kg, u = 0 m/s (Lillian was standing at rest), u' = 3.0 m/s.
Substitute into equation 2
V = (40×0+15×3)/(40+15)
V = (0+45)/55
V = 45/55
V = 0.82 m/s
