Help me plz, it's MATHS The car opposite is broke down. On wishes to move it by one point A to a point B. Four people push this car by exerting a force of the same norm but with different directions. Each person does not have the same efficiency for move the car from A to B. It is said that these forces do not exchange the same work.

1/ Rank the characters in order of effectiveness.

2/ To translate the efficiency of each force vector we

is interested in its orthogonal projection on the right hand side

(AB).

The orthogonal projection of the F1 vector was constructed on (AB) denoted P1

Do the same for the other vectors. What

is it consistent with the answer of 1. ?

3/ In order to quantify this efficiency, physicists calculate the

products of the AB standards by the projected standard

orthogonal of the force vector on (AB) if the 2 vectors are

in the same way. In the case where the 2 vectors are of direction

If not, the opposite of this product is calculated. This is

names the work of the force vector in Physics or the

scalar product of AB and F1 vectors in Mathematics.

Estimate graphically using question 2. the product

scalar of AB and F1, ... , F4

4/ To calculate the exact values of the scalar products, one can

uses the cosine to arrive at the definition of the product

scalar with norms and cosine.