Answer:
2 m/s
Explanation:
Parameters given:
Mass of first skateboard, m = 3 kg
Initial speed of first skateboard, u = 4 m/s
Mass of second skateboard, M = 1 kg
Initial speed of second skateboard, U = 0 m/s
Final speed of second skateboard, V = 6 m/s
Using the principle of the conservaton of momentum, the total initial momentum is equal to the total final momentum.
Momentum is the product of mass and velocity. This implies that:
m*u + M*U = m*v + M*V
(3*4) + (1*0) = (3*v) + (1*6)
12 + 0 = 3v + 6
=> 3v = 12 - 6
3v = 6
v = 6/3 = 2 m/s
The final speed of the 3 kg skateboard is 2 m/s
To find momentum you multiply the mass and velocity.
91 × 7 = 637 kg-m/s
It probably does. I'm not 100% sure about it, but a thicker wire would increase the number of positive and negative charges in it.
Answer: 
Explanation:
The answer is not among the given options. However, this is a good example of the relation between the energy stored in a capacitor 
and its capacitance 
, which is given by the following equation:
(1)
Where:
is the voltage
is the capacitance in Farads, the value we want to find
Isolating from (1):
(2)
(3)
Finally:
This is the capacitance of the cardiac defibrillator
