Answer: B - 8
Explanation: 8 protons because number of protons is equal to number of atoms in the nucleus.
Given parameters:
Mass of object = 6.7kg
Velocity = 8m/s
Unknown parameter:
Kinetic energy = ?
Energy is defined as the ability to do work. There are two forms of energy;
Kinetic and potential energy.
Kinetic energy is the energy due to the motion of a body. Whereas, potential energy is the energy due to the position of a body usually at rest.
Kinetic energy is mathematically expressed as;
Kinetic energy = 
where m is the mass of the body
v is the velocity of the body
Since we have been given both mass and velocity, input the parameter to solve for the unknown;
Kinetic energy =
x 6.7 x 8² = 214.4J
So the kinetic energy of the body is 214.4J
The force exerted on the board by the karate master given the data is -4500 N
<h3>Data obtained from the question </h3>
- Initial velocity (u) = 10 m/s
- Final velocity (v) = 1 m/s
- Time (t) = 0.002 s
- Mass (m) = 1 Kg
- Force (F) = ?
<h3>How to determine the force</h3>
The force exerted can be obtained as illustrated below:
F = m(v - u) / t
F = 1 (1 - 10) / 0.002
F = (1 × -9) / 0.002
F = -4500 N
Learn more about momentum:
brainly.com/question/250648
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