Question

Calculate the change in the kinetic energy (KE) of the bottle when the mass is increased. Use the formula
KE = one half.mv2, where m is the mass and v is the speed (velocity). Assume that the speed of the soda bottle falling from a height of
0.8 m will be 4 m/s, and use this speed for each calculation.

Record your calculations in Table A of your Student Guide.

When the mass of the bottle is 0.125 kg, the KE is
kg m2/s2.

When the mass of the bottle is 0.250 kg, the KE is
kg m2/s2.

When the mass of the bottle is 0.375 kg, the KE is
kg m2/s2.

When the mass of the bottle is 0.500 kg, the KE is

kg m2/s2.

Answer 1

KE = 1/2 m v^2 with v = 4 m/s ⇒ v^2 = 16, so KE = 8 m (J).

- m = 0.125 kg: KE = 8(0.125) = 1.0 J (1.0 kg·m^2/s^2).
- m = 0.250 kg: KE = 8(0.250) = 2.0 J (2.0 kg·m^2/s^2).
- m = 0.375 kg: KE = 8(0.375) = 3.0 J (3.0 kg·m^2/s^2).
- m = 0.500 kg: KE = 8(0.500) = 4.0 J (4.0 kg·m^2/s^2).

Change in KE for each 0.125 kg increase in mass = +1.0 J.