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).
Disease
Lack of natural reourses
war
asteroid
Polution.
Answer:
Average acceleration on first part of the chunk is given as
Average acceleration on second part of the chunk is given as
Explanation:
By momentum conservation along x direction we will have
so we have
also by energy conservation
by solving above equation we will have
Average acceleration on first part of the chunk is given as
Average acceleration on second part of the chunk is given as
Answer:
(a)11.24 m/s
(b)7.44 m/s
(c)409 N
(d)
(e) 0
Explanation:
The period for 1 circle 
of the merry go around is 9.5s. It means the angular speed is:
(a)The speed is
(b) Centripetal acceleration:
(c) Magnitude of the force that keeps you go around at this acceleration
(d) let the coefficient of friction by 
. The frictional force shall be this coefficient multiplied by normal force reverting gravity of the man
Answer:
Graph C
Explanation:
With the same force and more mass, the position in time will still be parabolic
i.e. x = ½at², but the rate of acceleration will be lower so the position curve will be broader.
