Index fossils are used to determine the relative ages of rock and fossils and are also used to define the boundaries between geologic periods.
<u>Option: A</u>
<u>Explanation:</u>
The fossils which are recognized as fossils guides or indicator fossils are used to classify and recognize geological or faunal periods, termed as index fossils. It must be of short vertical reach, wide geographic distribution and swift patterns in evolution. It helps to assess the rock layers ' age and helps to date other fossils found close and around them. For an instance, Ammonites were abundant in the Mesozoic period between 245 to 65 mya, they have not been found after the Cretaceous era, as they became endangered during the K-T extinction (65 mya).
Mechanical advantage is defined as the ratio of output load to the input load. The mechanical advantage of the machine will be 0.1.
<h3>What is
mechanical advantage?</h3>
Mechanical advantage is a measure of the ratio of output force to input force in a system,
It is used to obtain the efficiency of forces in levers and pulleys. It is an effective way of amplifying the force in simple machines like levers.
The theoretical mechanical advantage is defined as the ratio of the force responsible for the useful work in the system to the applied force.
Given
applied force = 250 N
Output force = 25
Mechanical advantage = work output / work input



Hence the mechanical advantage of the machine will be 0.1
To learn more about the mechanical advantage refer to the link;
brainly.com/question/7638820
Answer:
2
Explanation:
A rigid body is not elastic.
i.e. it does not change shape.
The correct answer is the third, It reflects the green light waves and absorbs most of the rest.
Answer:
23. 4375 m
Explanation:
There are two parts of the rocket's motion
1 ) accelerating (assume it goes upto h1 height )
using motion equations upwards

Lets find the velocity after 2.5 seconds (V1)
V = U +at
V1 = 0 +5*2.5 = 12.5 m/s
2) motion under gravity (assume it goes upto h2 height )
now there no acceleration from the rocket. it is now subjected to the gravity
using motion equations upwards (assuming g= 10m/s² downwards)
V²= U² +2as
0 = 12.5²+2*(-10)*h2
h2 = 7.8125 m
maximum height = h1 + h2
= 15.625 + 7.8125
= 23. 4375 m