Answer: HP = Horse Power.
Explanation: it is the unit given to tell the motor's particular power and 1hp = 746 watts.
The potential energy of the block is given by:
V = m*g*h
m mass
g = 9.81m/s²
h height
The potential energy of a spring is given by:
V = 0.5 * k * x²
k spring constant
x compression of the spring
If the block starts from rest it has potential energy, but no kinetic energy. As it slides down the incline potential energy is converted into kinetic energy. When the block hits the spring the kinetic energy is converted into spring's potential energy. If the spring is fully compressed and the block is at rest again, the block has transferred all its energy into the spring. No energy is lost. So we can write:
m * g * h = 0.5 * k * x²
m = 0.5 kg
g = 9.81 m/s²
h = 2.5m * sin 37° = 1,5 m
x = 0,6 m
Solve for k.
k = 2 * m * g * h / x² = 40.8 N/m
Work = (force) x (distance)
62,500 joules = (boulder's weight) x (25 meters)
Divide each side by (25 meters) :
Boulder's weight = (62,500 joules) / (25 meters) = <u>2,500 newtons</u>
That's about 562 pounds.