A 6.5-g iron meteor hits the earth at a speed of 295 m/s. If its kinetic energy is entirely converted to heat in the meteor, by how much will its temperature rise? The specific heat of iron is 113 cal/kg ∙ C°, and 1 cal = 4.186 J.
A) 92.0 C°
B) 57,100 C°
C) 0.147 C°
D) 384 C°

Question

Quizplus · Accepted Answer

The kinetic energy (KE) of the meteor is converted to heat (Q). KE = 0.5 * m * v^2 = 0.5 * 0.0065 kg * (295 m/s)^2 = 282.0375 J. Convert this to calories: 282.0375 J / 4.186 J/cal = 67.42 cal. The temperature rise (ΔT) is given by Q = mcΔT, where m = 0.0065 kg and c = 113 cal/kg°C. Solving for ΔT gives ΔT = Q / (m * c) = 67.42 cal / (0.0065 kg * 113 cal/kg°C) = 92.0°C.

A 65-G Iron Meteor Hits the Earth at a Speed of of 295