Answer:
(a) The total energy of the object at any point in its motion is 0.0416 J
(b) The amplitude of the motion is 0.0167 m
(c) The maximum speed attained by the object during its motion is 0.577 m/s
Explanation:
Given;
mass of the toy, m = 0.25 kg
force constant of the spring, k = 300 N/m
displacement of the toy, x = 0.012 m
speed of the toy, v = 0.4 m/s
(a) The total energy of the object at any point in its motion
E = ¹/₂mv² + ¹/₂kx²
E = ¹/₂ (0.25)(0.4)² + ¹/₂ (300)(0.012)²
E = 0.0416 J
(b) the amplitude of the motion
E = ¹/₂KA²

(c) the maximum speed attained by the object during its motion

Answer:
The displacement of the train in this time period is 2,616.86 m.
Explanation:
A Uniformly Varied Rectilinear Motion is Rectilinear because the mobile moves in a straight line, Uniformly because of there is a magnitude that remains constant (in this case the acceleration) and Varied because the speed varies, the final speed being different from the initial one.
In other words, a motion is uniformly varied rectilinear when the trajectory of the mobile is a straight line and its speed varies the same amount in each unit of time (the speed is constant and the acceleration is variable).
An independent equation of useful time in this type of movement is:
<em>Expression A</em>
where:
- vf = final velocity
- vi = initial velocity
- a = acceleration
- d = distance
The equation of velocity as a function of time in this type of movement is:
vf=vi + a*t
So the velocity can be calculated as: 
In this case:
- vf=42.4 m/s
- vi=27.5 m/s
- t=75 s
Replacing in the definition of acceleration: 
a=0.199 m/s²
Now, replacing in expression A:

Solving:

d= 2,616.86 m
<u><em>The displacement of the train in this time period is 2,616.86 m.</em></u>
Answer:
2270 full wavelengths.
Explanation:
The wavelength
of the sound wave (assuming sound speed of
) is

.
Now, assuming the distance to the last row is 1947m, the number
of wavelengths that fit into this distance are


which is 2270 full wavelengths.
Hence, there are 2270 full wavelengths between the stage and the last row of the crowd.
Hey there! A pure substance can be a element.
Hope this helps! :)