Question

 A constant force 𝑮⃗ ⃗

= (𝟓. 𝟏𝟏𝒋̂ + 𝟔. 𝟏𝟏 𝒌 ̂)𝑵 is applied to a particle that

undergoes a displacement 𝓵⃗ ⃗ ⃗

= (𝟒. 𝟏𝟏𝒋̂  − 𝟕. 𝟏𝟏 𝒌 ̂)𝒏. (a) the work done by 

the force, and (b) the component of the force in the direction of the 

displacement.

Answer 1

(a) The work is

$$W=\vec G·\vec l=5.11·4.11+6.11·(-7.11)= 27.1\text { J}.$$

(b) The component of the force is

$$G_l=W/|l|=27.1/\sqrt{4.11^2+7.11^2}=3.30\text{ N}.$$