Atoy car with a mass of 2kg starts at rest. a spring performs 196 joules of work on the car. what is the toy cars final velocity

W = work done by the spring on the toy car = 196 Joules

m = mass of the toy car = 2 kg

v₀ = initial velocity of the car when at rest = 0 m/s

v = final velocity of the car after spring does work on it = ?

According to work-change in kinetic energy, net work done on an object is same as the change in kinetic energy of the object . hence

Net work done = Final kinetic energy - initial kinetic energy

W = (0.5) m (v² - v₀²)

inserting the values

196 = (0.5) (2) (v² - (0)²)

v² = 196

v = sqrt(196)

v = 14 m/s

d.7.5cm is your answer