Question

A 20%-efficient car engine accelerates the 1300 kg car from rest to 13 m/s. How much energy is transferred to the engine by burning gasoline?

Answer 1

Answer:

The energy transferred to the engine by burning gasoline is 549250 J.

Explanation:

Given that,

Mass of car = 1300 kg

Speed = 13 m/s

We need to calculate the change in kinetic energy

Using formula of change in kinetic energy

$\Delta K.E=\dfrac{1}{2}mv_{f}^{2}-\dfrac{1}{2}mv_{i}^2$

Where, m = mass

v = speed

Put the value into the formula

$\Delta K.E=\dfrac{1}{2}\times1300\times(13)^2$

$\Delta K.E=109850\ J$

We need to calculate the heat energy

Using formula of efficiency

$\eta=\dfrac{W}{E}$

$E=\dfrac{W}{\eta}$

Put the value into the formula

$E=\dfrac{109850\times100}{20}$

$E=549250\ J$

Hence, The energy transferred to the engine by burning gasoline is 549250 J.