Acopper sample in the form of a prism has the following dimensions: length, 1.25 m; width, 1.25 m; height, 2.15 m. if the density of copper is reported as 8.9 g/cm3, calculate, using dimensional analysis, the mass of the sample in kilograms.

= 29,898.4375 Kg

Volume of a prism is given by the formula;

V = base area × height

   = 1.25 m × 1.25 m × 2.15 m

   = 3.359375 m³

Density = 8.9 g/cm³

This is equivalent to ; 8900 kg/m³

Therefore;

Mass = Density × volume

         = 8900 kg/m³ × 3.359375 m³

         = 29,898.4375 Kg

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j