The figure shows a person whose weight is W = 670 N doing push-ups. Find the normal force exerted by the floor on (a) each hand and (b) each foot, assuming that the person holds this position.
To find the normal force exerted by the floor on each hand and each foot, we need to consider the forces acting on the person and make use of Newton's second law, which states that the sum of the forces on an object is equal to its mass multiplied by its acceleration.
Let's start with the person's hand. In order for them to hold the push-up position, the upward normal force exerted by the floor on each hand must balance out the person's weight (W). Therefore, the normal force exerted by each hand (NH) can be calculated as:
NH = W/2
Since there are two hands, we divide the weight by 2.
NH = 670 N / 2
NH = 335 N
So, the normal force exerted by the floor on each hand is 335 N.
Now let's move on to the person's foot. Similar to the hands, the upward normal force exerted by the floor on each foot must balance out the person's weight (W). Therefore, the normal force exerted by each foot (NF) can be calculated as:
NF = W/2
NF = 670 N / 2
NF = 335 N
So, the normal force exerted by the floor on each foot is 335 N.
In summary:
(a) The normal force exerted by the floor on each hand is 335 N.
(b) The normal force exerted by the floor on each foot is also 335 N.