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).
Answer:
The electric flux is 
Explanation:
Given:
- Radius of the disc R=0.50 m
- Angle made by disk with the horizontal
- Magnitude of the electric Field
The flux of the Electric Field E due to the are dA in space can be found out by using Gauss Law which is as follows
where
is the total Electric Flux- E is the Electric Field
- dA is the Area through which the electric flux is to be calculated.
Now according to question we have
Hence the electric flux is calculated.
The change in pitch of a train's horn as it passes while you are
standing still can be described by the Doppler effect, but that
doesn't explain it.
Answer:
0.438kg/ms-¹
Explanation:
Momentum, denoted by p, can be calculated by using the formula;
p = mv
Where;
m = mass (kg)
v = velocity (m/s)
Momentum (p) of bird = 0.216 kg × 5.87 m/s = 1.268kg/ms-¹
Momentum (p) of crawling baby = 7.29 kg kg × 0.234 m/s = 1.706kg/ms-¹
Having calculated the momentum of the bird to be 1.268kg/ms-¹, and the momentum of the baby to be 1.706kg/ms-¹, the difference in momentum between the flying bird and the crawling baby is:
{1.706kg/ms-¹ - 1.268kg/ms-¹} = 0.438kg/ms-¹
