Answer:
the third one is incorrect
Explanation:
10 x 10³= 10^1 x 10^3 = 10^4
The broom handle that she have to balance if she hung a 400g mass from the end of the broom handle is 5.24m
This problem is centered on moment. Moment is the turning effect of a force about a point. It is expressed as:
Moment = Force× Distance
According to principle of moment, the sum of clockwise moment is equal to sum of anticlockwise moment at shown
M1d1 = M2d2
Given the following
M1 = 1.5kg
d1 = 1.4m
M2 = 400g = 0.4kg
d2 is required
Substitute
1.5(1.4) = 0.4d2
2.1 = 0.4d2
d2 = 2.1/0.4
d2 = 5.24m
Hence the broom handle that she have to if she hung a 400g mass from the end of the broom handle is 5.24m
Learn more here: brainly.com/question/21945515
Answer:
The charge stored in the capacitor will stay the same. However, the electric potential across the two plates will increase. (Assuming that the permittivity of the space between the two plates stays the same.)
Explanation:
The two plates of this capacitor are no longer connected to each other. As a result, there's no way for the charge on one plate to move to the other. 
, the amount of charge stored in this capacitor, will stay the same.
The formula 
relates the electric potential across a capacitor to:
- , the charge stored in the capacitor, and
, the capacitance of this capacitor.
While stays the same, moving the two plates apart could affect the potential 
by changing the capacitance of this capacitor. The formula for the capacitance of a parallel-plate capacitor is:
,
where
is the permittivity of the material between the two plates.
is the area of each of the two plates.
is the distance between the two plates.
Assume that the two plates are separated with vacuum. Moving the two plates apart will not affect the value of . Neither will that change the area of the two plates.
However, as (the distance between the two plates) increases, the value of will become smaller. In other words, moving the two plates of a parallel-plate capacitor apart would reduce its capacitance.
On the other hand, the formula can be rewritten as:
.
The value of (charge stored in this capacitor) stays the same. As the value of becomes smaller, the value of the fraction will become larger. Hence, the electric potential across this capacitor will become larger as the two plates are moved away from one another.
Answer:
a. The total momentum of the trolleys which are at rest before the separation is zero
b. The total momentum of the trolleys after separation is zero
c. The momentum of the 2 kg trolley after separation is 12 kg·m/s
d. The momentum of the 3 kg trolley is -12 kg·m/s
e. The velocity of the 3 kg trolley = -4 m/s
Explanation:
a. The total momentum of the trolleys which are at rest before the separation is zero
b. By the principle of the conservation of linear momentum, the total momentum of the trolleys after separation = The total momentum of the trolleys before separation = 0
c. The momentum of the 2 kg trolley after separation = Mass × Velocity = 2 kg × 6 m/s = 12 kg·m/s
d. Given that the total momentum of the trolleys after separation is zero, the momentum of the 3 kg trolley is equal and opposite to the momentum of the 2 kg trolley = -12 kg·m/s
e. The momentum of the 3 kg trolley = Mass of the 3 kg Trolley × Velocity of the 3 kg trolley
∴ The momentum of the 3 kg trolley = 3 kg × Velocity of the 3 kg trolley = -12 kg·m/s
The velocity of the 3 kg trolley = -12 kg·m/s/(3 kg) = -4 m/s
Answer:
the cost of operating the light bulb is 72 cents.
Explanation:
Given;
cost of electricity, C = 6 cents / kW.h
power of light bulb, P = 100 W
time of light power consumption, t = 4 hours per day for 30 days
total time = 4 hours x 30 = 120 hours
Power consumed by the light bulb is calculated as;
P = 100 x 120 = 12000 w.h = 12 kW.h
Cost of power consumption = 6 cents/kWh x 12 kWh
= 72 cents
Therefore, the cost of operating the light bulb is 72 cents.
