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3 years ago

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A 750-kg car moving at 23 m/s brakes to a stop. Assume that all the kinetic energy is transformed into thermal energy. The brake

s contain about 15 kg of iron, which absorbs the energy. What is the increase in temperature of the brakes?

1 answer:

ahrayia [7]3 years ago

7 0

Answer:

The temperature of the brakes is 29.38°C.

Explanation:

Given that,

Mass of car = 750 kg

Speed = 23 m/s

Mass of iron = 15 kg

We need to calculate the kinetic energy of car

Using formula of kinetic energy

$K.E=\dfrac{1}{2}mv^2$

$K.E=\dfrac{1}{2}\times750\times23^2$

$K.E=198.375\ kJ$

We need to calculate the temperature of the brakes

Using formula of energy

$K.E=mc\Delta T$

Put the value into the formula

$198.375=15\times0.450\times\Delta T$

$\Delta T=\dfrac{198.375}{15\times0.450}$

$\Delta T=29.38^{\circ}C$

Hence, The temperature of the brakes is 29.38°C.

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<h3>a) Mass of the continent</h3>

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