Question

A 5.00 kg lead sphere is dropped from the top of a 60.0-m-tall building.

Part A

If all of its kinetic energy is converted into heat when it hits the sidewalk, how much will its temperature rise? (Ignore air resistance.)

Express your answer in degrees celsius to three significant figures.

ΔT ΔT =		∘C

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Answer 1

Kinematic and specific heat equations are used to calculate the rise of temperature of the sphere.

The kinematic equation used here is,

Here, v and u ate the final and initial velocities of the object, g is the acceleration due to gravity and h is the height.

Since the ball is dropped from the top of a building, it's initial velocity u = 0.

Now, substituting the values in the equation,

= 34.29 m/s

The equation for kinetic energy of the ball,

  

Substituting the values,

  

= 2939.5 J

Since all the kinetic energy is converted into heat,

Q = E = 2939.5 J

The specific heat equation is given by,

where m is the mass, c is the specific heat and is the change in temperature.

For lead, c = 129 J/kg°C

Now, the rise in temperature,

  

=4.56°C