Answer:
a. 4
Explanation:
Hi there!
The equation of kinetic energy (KE) is the following:
KE = 1/2 · m · v²
Where:
m = mass of the car.
v = speed of the car.
Let´s see how would be the equation if the velocity is doubled (2 · v)
KE2 = 1/2 · m · (2 · v)²
Distributing the exponent:
KE2 = 1/2 · m · 2² · v²
KE2 = 1/2 · m · 4 · v²
KE2 = 4 (1/2 · m · v²)
KE2 = 4KE
Doubling the velocity increased the kinetic energy by 4.
Answer:
Explanation:
Let the resistance of resistor be R .
Power of resistor V² / R , where V is potential applied .
V² / R = 100
120² / R = 100
R = 120² / 100
= 144 ohm .
Now potential diff applied = 220 V
current = potential diff / resistance
= 220 / 144
= 1.53 A approx .
Answer: B, increase the rate at which he turns the crank
Explanation: i got it right
