Answer:
<u>7.2 m</u>
Explanation:
In this scenario, the man possesses kinetic energy as he is in motion.
⇒ KE = 1/2mv²
His potential energy will be equal to the kinetic energy as per the law of conservation of energy.
So, 1/2mv² = mgh [potential energy]
⇒ v²/2 = gh
⇒ h = v²/2g
⇒ h = (12)²/2(10)
⇒ h = 144/20
⇒ h = <u>7.2 m</u>
The difference between the maximum and minimum values of voltage V across the 3 ohm resistor would be 9V.
To find the minimum and maximum values of V across the 3 ohm resistor, you will need to use Ohm’s Law, V=IR.
You already know the resistance is 3 ohms across the resistor; in order to calculate the maximum/minimum voltage across it, you will need to work out the maximum/minimum current of the series circuit.
Using Ohm’s Law to find the maximum and minimum current:
I = V/R
Where:
V = 12V (this is the emf, no volts are lost to the cell because the cell has a negligible internal resistance therefore all the 12V is transferred to the resistors in the circuit.)
The value for R however, changes due to the resistance in the variable resistor varying from 0 to 9 ohms.
The minimum value of R would be 3 ohms, where the resistance of the variable resistor is 0. Therefore total resistance = 3 + 0 = 3 ohms
Maximum value of R would be 12 ohms, where the resistance of the variable resistor is at a maximum of 9 ohms. Therefore total resistance = 3 + 9 = 12 ohms
The rest of the explanation is in the picture, hope it makes sense