Light will travel more slowly in a material with a higher index of refraction
Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:

where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,

Now, we will calculate the number of uranium nuclei left (
):

and the rest of the uranium nuclei will become thorium nuclei (
)

dividing both:

<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>
Answer:

Explanation:
Given:
dimension of uniform plate, 
mass of plate, 
Now we find the moment of inertia about the center of mass of the rectangular plate is given as:

where:
length of the plate
breadth of the plate


We know that the center of mass of the rectangular plane is at its geometric center which is parallel to the desired axis XX' .
Now we find the distance between the center of mass and the corner:


Now using parallel axis theorem:



the answer is concave lens
Answer:
k = 4422.35 KN/m
Explanation:
Given that
Frequency ,f= 29 Hz
m = 7.5 g
Natural frequency ω
ω = 2 π f
We also know that for spring mass system
ω ² m =k
k=Spring constant
So we can say that
( 2 π f)² = m k
By putting the values
(2 x π x 29)² = 7.5 x 10⁻³ k
33167.69 = 7.5 x 10⁻³ k
k=4422.35 x 10³ N/m
k = 4422.35 KN/m
Therefore spring constant will be 4422.35 KN/m