The problem involves the conversion of potential energy to kinetic energy as the object falls from rest. Energy is conserved, so the equation used is:
PEi + KEi = PEf + KEf
Since the object is falling from rest, the initial kinetic energy is zero. Also, since the object hits the ground at its final position, the final potential energy is zero. This leaves:
PEi = KEf
mgh = 1/2 mv^2
*cancel out mass on both sides of the equation
gh = 0.5v^2
v = sqrt(2gh) = sqrt(2*9.81*4.5) = 9.40 m/s --> final ans.
Weight (that's what the 500 N is) = (mass) x (gravity) .
On Earth, gravity = about 9.8 m/s² , so
500 N = (mass) x (9.8 m/s²) .
Divide each side by 9.8 m/s²:
Mass = (500 N) / (9.8 m/s²)
= 51 kg (rounded) .
Radiation is the flow of energy by means of electromagnetic waves.
Taking the vertical component of the displacement
1.1 - 0.2 = 0.9 mile
The horizontal component of the displacement
-0.3 mile
The magnitude of the displacement is
√[ (0.9)² + (-0.3) ] = 0.95 mile
The direction is
θ = tan-1 (-0.3/0.9)
θ = 161.57 degrees.
Answer:
Temperature decreases because the number of collision of the molecules decreases as they escape or evaporate. Molecules are in constant motion. Increase in temperature leads to increase in average kinetic energy of the molecules.
