Answer:
Athlete A
Explanation:
Power is the rate of doing work and it is calculated as follows:
Power = work done/time taken = mgh/t
(for work being done against gravity)
So for athlete A
P = (100 kg * 9.8 N/kg* 0.6m)/0.5 s = 1176 W
For athlete B
P = (150 kg * 9.8 N/kg* 0.6m)/1 s = 882 W
For athlete C
P = (200 kg * 9.8 N/kg* 0.6m)/2 s = 588 W
For athlete D
P = (250 kg * 9.8 N/kg* 0.6m)/2.5 s = 588
Answer:
Explanation:
The capacitance of a parallel plate capacitor is given by:
(1)
where
is the vacuum permittivity
A is the area of the plates
d is the separation between the plates
The charge stored on the capacitor is given by
(2)
where C is the capacitance and V is the voltage across the capacitor.
The displacement current in the capacitor is given by
(3)
where t is the time elapsed
Substituting (1) and (2) into (3), we find an expression for the displacement current:
where we have
Substituting into the equation, we find
<span> The box is exerting a force of its weight. So we'll use W=mg (Note: you can use the notation F=ma, doesn't matter since weight IS a force.) We can call g negative since it's directed down towards the earth.
</span>
<span>W = 5kg(-9.8 m/(s^2)) = -49 N
</span>
<span>Thus, the box exerts a force of 49N downwards. </span>
Answer:
90 A
Explanation:
Applying,
P = VI.............. Equation 1
Where P = Power, V = Supply voltage, I = current.
Make I the subject of the equation
I = P/V.............. Equation 2
From the question,
Assuming the Voltage of the main electric supply is 120 V
Given: P = 10.8 kW = 10800 W, V = 120 V (household voltage)
Substitute these values into equation 2
I = 10800/120
I = 90 A
During the first collision, the vehicle comes to an abrupt stop.
