Answer:
Explanation:
This is a circular motion questions
Where the oscillation is 27.3days
Given radius (r)=3.84×10^8m
Circular motion formulas
V=wr
a=v^2/r
w=θ/t
Now, the moon makes one complete oscillation for 27.3days
Then, one complete oscillation is 2πrad
Therefore, θ=2πrad
Then 27.3 days to secs
1day=24hrs
1hrs=3600sec
Therefore, 1day=24×3600secs
Now, 27.3days= 27.3×24×3600=2358720secs
t=2358720secs
Now,
w=θ/t
w=2π/2358720 rad/secs
Now,
V=wr
V=2π/2358720 ×3.84×10^8
V=1022.9m/s
Then,
a=v^2/r
a=1022.9^2/×3.84×10^8
a=0.0027m/s^2
Answer:
refractive index of the unknown material is 1.33.
Explanation:
μ₁ = 1.21
incidence angle (i) = 41.9°
refraction angle (r) = 37.3°
Let us assume μ be the refractive index of the unknown material
according to snell's law of refraction.
μ₁ sin i = μ₂ sin r
1.21 × sin 41.9° = μ × sin 37.3°
μ = 1.33
hence the refractive index of the unknown material comes out top be 1.33
Answer: The correct answers are (A) and (C).
Explanation:
The expression from electrostatic force is as follows;

Here, F is the electrostatic force, k is constant, r is the distance between the charges and
are the charges.
The electrostatic force follows inverse square law. It is inversely proportional to the square of the distance between the charges. It is directly proportional to the product of the charges.
Like charges repel each other. There is a force of electrostatic repulsion between the like charges. Unlike charges attract each other. There is a force of electrostatic attraction between unlike charges.
The charges are induced on the neutral object when it is placed nearby the charged object without actually touching it.
Therefore, the true statements from the given options are as follows;
Like charges repel.
Unlike charges attract.
Given that : d = 5sin(pi t/4), So, maximum displacement, d = 5*(+1) = 5 Also, maximum displacement, d = 5*(-1) = -5
Answer:
The statement is true: velocity and acceleration have opposite directions in the interval of braking.
Explanation:
Let's say we have a velocity
.
The acceleration
is the rate of change of the velocity
. This means that if
is <em>increasing during</em> time, then
must be positive. But if
is <em>decreasing over</em> time, then
will be negative (even though the velocity is positive).
Mathematically:

decreases ⇒
⇒
.
Example:
