Answer:
d²x/dt² = - 4dx/dt - 4x is the required differential equation.
Explanation:
Since the spring force F = kx where k is the spring constant and x its extension = 2.45 equals the weight of the 4 kg mass,
F = mg
kx = mg
k = mg/x
= 4 kg × 9.8 m/s²/2.45 m
= 39.2 kgm/s²/2.45 m
= 16 N/m
Now the drag force f = 16v where v is the velocity of the mass.
We now write an equation of motion for the forces on the mass. So,
F + f = ma (since both the drag force and spring force are in the same direction)where a = the acceleration of the mass
-kx - 16v = 4a
-16x - 16v = 4a
16x + 16v = -4a
4x + 4v = -a where v = dx/dt and a = d²x/dt²
4x + 4dx/dt = -d²x/dt²
d²x/dt² = - 4dx/dt - 4x which is the required differential equation
Answer:
The distance from the radio station is 0.28 light years away.
Solution:
As per the question:
Distance, d = 4 ly
Frequency of the radio station, f = 854 kHz = 
Power, P = 50 kW = 

Now,
From the relation:
P = nhf
where
n = no. of photons/second
h = Planck's constant
f = frequency
Now,

Area of the sphere, A = 
Now,
Suppose the distance from the radio station be 'r' from where the intensity of the photon is 



Now,
We know that:
1 ly = 
Thus

Answer:
<em>The distance the car traveled is 21.45 m</em>
Explanation:
<u>Motion With Constant Acceleration
</u>
It occurs when an object changes its velocity at the same rate thus the acceleration is constant.
The relation between the initial and final speeds is:
![v_f=v_o+at\qquad\qquad [1]](https://tex.z-dn.net/?f=v_f%3Dv_o%2Bat%5Cqquad%5Cqquad%20%5B1%5D)
Where:
a = acceleration
vo = initial speed
vf = final speed
t = time
The distance traveled by the object is given by:
![\displaystyle x=v_o.t+\frac{a.t^2}{2}\qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3Dv_o.t%2B%5Cfrac%7Ba.t%5E2%7D%7B2%7D%5Cqquad%5Cqquad%20%5B2%5D)
Solving [1] for a:

Substituting the given data vo=0, vf=6.6 m/s, t=6.5 s:


The distance is now calculated with [2]:

x = 21.45 m
The distance the car traveled is 21.45 m
Answer:
- When an object experiences acceleration to the left, the net force acting on this object will also be to the left.
- If the mass of the object was doubled, it would experience an acceleration of half the magnitude
Explanation:
When an object experiences acceleration to the left, the net force acting on this object will also be to the left.
From Newton's second law of motion, the acceleration of the object is given as;
a = ∑F / m
a = -F / m
The negative value of "a" indicates acceleration to the left
where;
∑F is the net force on the object
m is the mass of the object
At a constant force, F = ma ⇒ m₁a₁ = m₂a₂
If the mass of the object was doubled, m₂ = 2m₁
a₂ = (m₁a₁) / (m₂)
a₂ = (m₁a₁) / (2m₁)
a₂ = ¹/₂(a₁)
Therefore, the following can be deduced from the acceleration of this object;
- When an object experiences acceleration to the left, the net force acting on this object will also be to the left.
- If the mass of the object was doubled, it would experience an acceleration of half the magnitude