Answer:
D
Explanation:
By law of conservation of momentum:
momentum before collision = momentum after collision

Initial speed of bullet is unknown whereas initial speed of pendulum will be zero as it was at rest.
Final speed of bullet and pendulum will be equal as bullet is embedded in pendulum and both moves together a vertical distance of 6.89cm.
Using third equation of motion:

where:

Thus by placing values 
this speed will be final speed of collision for the calculation of initial speed of bullet.
Putting values:

This 224m/s = 0.224Km/s which is closest to D
Answer:
F = 2.3 x 10⁻⁸ N
Explanation:
Given,
The mean distance between the electron and the nucleus, x = 1 x 10⁻¹⁰ m
The number of protons present in the nucleus of the hydrogen atom is 1.
The charge of the proton and electron, q = 1.602 x 10⁻¹⁹ C
Since they have opposite charges, the force between them is attractive,
The coulomb law of force between two charges is given by the formula,
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= 9 x 10⁹ Nm²C⁻²
Substituting the values in the above equation
F = 9 x 10⁹ X (1.602 x 10⁻¹⁹)² / (1 x 10⁻¹⁰)²
= 2.31 x 10⁻⁸ N
Hence, the force between the nucleus and electron of hydrogen atom is, F = 2.3 x 10⁻⁸ N
Answer: Atmosphere and geosphere.
Geo-sphere is the solid part of the earth. Hydrosphere is the water part. The living things on the earth make up the biosphere. The gases, water vapors etc make up the atmosphere. When a volcanic eruption adds carbon dioxide to the air, the carbon-dioxide is being added from geosphere to the atmosphere. Hence, there is interaction between atmosphere and geosphere.
Answer:
C. Earth give me brainlest its correct! Hope this helps!
Explanation:
Answer:
what is the action and reaction ?
Explanation: