Please help me with these questions

6. Determine the work done by a 62 kg cyclist who changes the speed of a 12 kg bicycle from B.2 m's In 12.7 mis. M = ( 7 . 8 ) ( 62 + 12 ) 725.2 W = Fix & marks 7. A cer, travelling at constant speed on a straight, level road, accelerates so that its speed is now doubled. By what factor will the car's kinetic energy change? Explain by using physics principles. 2 marks