# Biomechanics

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An 88.9 kg weight lifter is required to perform a snatch movement for their final lift in a weight lifting competition. The standard weight lifting bar is 20 kg and the load attached to the bar was in the form of 6 x 20 kg weight discs, 2 x 10 kg weight discs, 2 x 5 kg weight discs and 2 x 1.25 kg weight discs, with the discs evenly distributed on either side of the bar. The tallest weight disc was 50 cm and the bar was loaded in the centre of the tallest disc and then each subsequent disc was loaded. The snatch lift required the fully loaded bar to be moved from the floor to the competitors lifting height of 2.72 m. The successful lift was completed in 1.48 s. At the completion of the lift the weight lifter is standing on both feet with the load above the head, the weight lifters specialized shoes contact the ground with an area of 13 cm2.

(a) What was the weight of the weight lifter?

(b) How much work was done by the weight lifter?

(c) How much power was developed by the weight lifter?

(d) How much momentum did the lift produce?

(e) When the weight was held overhead what was the potential energy?

(f) What was the kinetic energy at this point?

(g) How much pressure is being exerted on the weight lifter as they stand with the load?