Ayoung boy of mass m = 25 kg sits on a coiled spring that has been compressed to a length 0.4 m shorter than its uncompressed length and then held at this length. suddenly the spring is released, and the boy flies vertically into the air. he reaches a maximum distance 0.5 m above his initial position. the spring is ideal and massless and we ignore the air friction.

what is the spring constant k of the spring?

what is the speed of the boy when he is 0.4 meters above his starting position?

We will use a video to study faraday’s law of electromagnetic induction by analyzing the induction that occurs due a coil of copper wire sliding along an air track that passes through an external magnetic field. specifically, we will: examine some of the main principles behind faraday’s law. apply lenz’s law to determine the direction of the induced emf. take measurements of the induced emf from the voltmeter as the coil passes into and out of the external magnetic field. use the horizontal scale provided to determine the speed of the coil. calculate the magnetic field induced in the coil as it passes into and out of the external magnetic field.