Question

find the angle between force F = (3i+4j-5k)unit and displacement d = (5i+4j+3k)unit. find the projection of force on d​

Answer 1

Answer:

F

.

d

=Fdcosθ

⟹cosθ=

Fd

F

.

d

=

50

15+16+15

=

50

46

⟹θ=cos

−1

0.92

Projection of

F

on

d

is given by

d

F

.

d

=

5

2

+4

2

+3

2

15+16+15

=

5

2

46