Amethyst... because it's silicon dioxide
Answer:
Option A. 39.2 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) = 4 s
Final velocity (v) =?
v = u + gt
Since the initial velocity (u) is 0, the above equation becomes:
v = gt
Thus, inputting the value of g and t, we can obtain the value of v as shown below:
v = 9.8 × 4
v = 39.2 m/s
Therefore, the velocity of the ball at 4 s is 39.2 m/s.
Answer:
The tension on the string is
Explanation:
From the question we are told that
The mass of the rock is 
The density of the rock is
Generally the volume of the rock is mathematically evaluated as

substituting values


The volume of the rock immersed in water is
substituting values


mass of water been displaced by the this volume is
According to Archimedes principle
=> 

The weight of the water displace is



The actual weight of the rock is

The tension on the string is
substituting values
Answer:
The stress is calculated as 
Solution:
As per the question:
Length of the wire, l = 75.2 cm = 0.752 m
Diameter of the circular cross-section, d = 0.560 mm = 
Mass of the weight attached, m = 25.2 kg
Elongation in the wire, 
Now,
The stress in the wire is given by:
(1)
Now,
Force is due to the weight of the attached weight:
F = mg = 
Cross sectional Area, A = 
Using these values in eqn (1):
All are examples of electromagnetic energy except <span>circles forming when a rock drops into a pool. The correct option among all the options that are given in the question is the third option or option "C". The other choices can be negated. I hope that this is the answer that has actually come to your help.</span>