Answer:
Power = Work / Time
P = 400 kg * 9.8 m/s * 4.5 m / 3600 sec = 4.9 J/s = 4.9 Watts
Also, 4.9 Watts / (746 Watts / Horsepower) = .0066 Hp
Answer:
Explanation:
Moving a magnet might cause a change in the magnetic field going through the solenoid. Whether or not it will change depends on the movement.
According to Faraday's law of induction a voltage is induced in a coil by a change in the magnetic flux. Magnetic flux is defined as the dot product of the magnetic field (a vector field) by the area enclosed by a loop of the coil.

The voltage is induced by the variation of the magnetic flux:

Where
ε: electromotive fore
N: number of turns in the coil
ΦB: magnetic flux
Moving the magnet faster would increase the rare of change of the magnetic flux, resulting in higher induced voltage.
Turning the magnet upside down would invert the direction of the magnetic field, reversing the voltage induced.
Answer:
pressure= force/area
A solid resting on a horizontal surfaceexerts a normal contactforce equals to its weight. The pressure of the solid on the surface depends on the area of contact. (b) the area of contact between the two surfaces. The greater the force or the smaller the area the greater the pressure.
Answer:
a principle stating that energy cannot be created or destroyed, but can be altered from one form to another.
Explanation:
I believe the answer would be mass. Low mass stars and medium mass stars often become white dwarfs when they die while high mass stars explode in violent explosions called supernovas and usually leave behind a black hole or a neutron star.