B, he has to apply less force to lift the box because the mass has decreased.
The equation for force is
F=ma
If m is decreased by half, then f decreases as well. It takes less force to push a lighter object across the floor.
Momentum = (mass) x (speed)
Momentum = (8 kg) x (5 m/s)
Momentum = 40 kg-m/s
I think the correct answer from the choices listed above is option B. The very high voltage needed to create a spark across the spark plug is produced at the transformer's secondary winding. <span>The secondary coil is engulfed by a powerful and changing magnetic field. This field induces a current in the coils -- a very high-voltage current.</span>
