Answer :
Final answer:
The kinetic energy of the child/tricycle system, with a mass of 42 kg and a speed of 3 m/s, is calculated as 189 J using the kinetic energy formula.
Explanation:
The kinetic energy of a child and tricycle system. Kinetic energy can be found using the formula KE = 1/2 mv2, where 'm' is mass and 'v' is velocity.
In this case, the mass (m) is 42 kg, and the velocity (v) is 3 m/s.
Plugging these values into the formula:
KE = 1/2 (42 kg) (3 m/s)2,
KE = 1/2 (42 kg) (9 m2/s2),
KE = 189 J.
Therefore, the correct answer is (c) 189 J.
