100 J of kinetic energy but no gravitational potential energy if GPE of the ground is assumed to be zero.
<h3>Explanation</h3>
Kinetic Energy
The ball carries kinetic energy for being in motion. The size of that energy is given as:
where
- is the mass of the object, and
- is its speed.
SI units:
- : joules.
- : kilograms.
- : meters per second.
For this ball:
.
Gravitational Potential Energy
Whether the ball carries gravitational potential energy depends on the point of zero potential energy. The ball would carry GPE if the point of zero potential energy is chosen underground. However, the question emphasizes that the ball is "on the ground," which <em>implies</em> that the ground is the reference with a GPE of zero.
The gravitational field near the Earth's surface is constant. As a result, GPE is proportional to height relative to the ground (or the point of zero GPE). The ball is on the ground. Its height is zero. As a result, its GPE is also zero.
Answer: F = 2917.2N
Explanation: To solve the question, we will employ Newton 2nd law of motion.
After hitting, the ball stop and no rebound.
The force exert by the ball is equal to the average force the fist will exert on the head.
Please find the attached file for the solution
Answer: B.
but the resistance is lower in the parallel circuit.
Explanation:
A circuit with parallel connections has a lower total resistance than the resistors connected in series. This is consistent with conservation of charge. The power dissipated by each resistor is considerably higher in parallel than when connected in series to the same voltage source.
The voltage across resistor is 75 volts, because you can solve this using the ohm law.
Hope this help!!
I believe your answer is d).
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