Flat bench

Flat Bench




The flat bench press is probably the most common lift and is a lift that is done in competitive power-lifting.  The motion of the flat bench is a straight up and down motion done at no angle.

The equation for work done for the flat bench would simply be W=FD, F being the force (N) and D being the displacement from the starting point (m).  To find the net force applied, it is equal to mass x acceleration. Based on this equation, it would make sense that the greater the distance the more work required implying that the lift with the shortest bar path must be the easiest to accomplish.

From the video analysis, it appears that the velocity was increasing constantly therefore there is constant acceleration.  The acceleration I derived was 4.241m/s^2.  I calculated this by using this equation : (Vf-Vi)/T.  Since the sum of the forces is in an upward direction, the equation would be ma + mg =Wp.  The reason being if you at the FBD, it is simply gravity downward, with a greater Force push upwards.  This force push is equal to that of the work being done.  adding the net force and the force of the mass, you can find the total newtons.  The total newtons I derived was 648.224.  This was my F, and then I multiplied this by .57 which was the distance to get 370.0585.  The power is the work divided by the time.  The time is .567.  The total watts generated from the lift is 652.660 Watts.