20.
The diagram shows the activity carried out by a student. The 2 kg trolley is pushed towards a wooden block so that the spring is compressed to 20 cm. The trolley is then released and the spring returns to its original length.If the force used to compress the spring is 60 N, calculate the velocity of the trolley after it is released. 12Fx = 12mv2\frac{1}{2}Fx\ =\ \frac{1}{2}mv^221Fx = 21mv2