# Calculate the increase in internal energy.A 0.8 kg spike is hammered into a railroad tie. The initial speed of the spike is equal to 3.3 m/s. (a) If the tie and spike together absorb 78 percent of...

Calculate the increase in internal energy.

A 0.8 kg spike is hammered into a railroad tie. The initial speed of the spike is equal to 3.3 m/s.

(a) If the tie and spike together absorb 78 percent of the spike's initial kinetic energy as internal energy, calculate the increase in internal energy of the tie and spike. Answer in Joules

(b) What happens to the remaining energy? Check all boxes that could absorb the remaining energy.

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### 1 Answer

A 0.8 kg spike is hammered into a railroad tie. The initial speed of the spike is equal to 3.3 m/s. The kinetic energy of the spike is equal to (1/2)*(0.8)*(3.3)^2 = 4.356 J

The tie and the spike absorb 78% of the spike's kinetic energy as internal energy. This gives the increase in the internal energy of the spike and the tie as 4.356*0.78 = 3.339768 J

The remaining energy which is 22% of the kinetic energy of the spike is converted to heat and dissipated into the surrounding atmosphere. It could be absorbed by the air, the ground and the hammer and results in an increase in their temperature.