A resistor DECREASES the speed of current as a resistors job is to resist the flow of electrons
1 Ampere
Explanation:
1/R = 1/8 + 1/10 + 1/12
1/R = (30 + 24 + 20) / 240
1/R = 74 / 240
R = 240 / 37
R = 120/37 Ohms
We know that,
V = IR
I = V/R
I = 12 / (120/37)
I = 12 × 37/120
I = 37/10
I = 3.7 A
Now,
The current in 12 ohm resistor →
= 1 A
∴ The current in 12 ohm resistor is 1 ampere
Answer:
1.40 N
Explanation:
The magnitude of the frictional force is given by:
where
is the coefficient of friction
N is the magnitude of the normal reaction
The coefficient of friction for this problem is 
. The magnitude of the normal reaction is equal to the combined weight of the boy and the sled, because the surface is horizontal, so
Therefore, the frictional force is
Answer:
The correct answer is - 200000 J
Explanation:
We use the formula of kinetic energy:
The formula to calculate kinetic energy is,
Here,
Ec =1/2 x m x v^2
The mass of the roller coaster is, m = 1000 k
g
The speed of the roller coaster is, v = 20.0 m/s
Therefore,
Ec=1/2 x 1000kg x (20m/s)^2 = 200.000Joule
200,000J
The first option.
The total mechanical energy before an action (which makes up PE and KE) equals the total mechanical energy after an action.
So
KEi + PEi = KEf + PEf
