A racing car has a mass of 1900 kg. The acceleration of gravity is 9.8 m/s2 . What is its kinetic energy if it has a speed of 118 km/h?Answer in units of J

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justaguide | College Teacher | (Level 2) Distinguished Educator

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A body in motion has kinetic energy. Kinetic energy can be due to linear motion as well as angular motion. We don't need the acceleration due to gravity to determine the kinetic energy of the car. Only the mass of the car and the speed it is moving at are enough.

The kinetic energy of the car is given by the expression: K.E. = (1/2)*m*v^2, where m is the mass and v is the velocity.

Here the mass of the car is 1900 kg.

The velocity of the car (we only need to consider the magnitude to arrive at the result) is 118 km/h

Convert the units from km/h to m/s

118*1000/3600 = 295/9 m/s

The kinetic energy is 0.5*1900*(295/9)^2 = 1020663.58 J

The kinetic energy of the car with a mass of 1900 kg traveling at a speed of 118 km/h is 1020.668 kJ.

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