Question

The vector −→k and −→x in the figure has a magnitude of 10.0 [m−1 ] and 5.00 [m], respectively. The vector −→k makes an angle of 35.0 ◦ with respect to the yaxis while the vector −→x makes an angle of 15.0 ◦ with respect to the x-axis. What is the scalar product, −→k · −→x ?

Answer 1

Solution.

$\vert\overrightarrow{k}\vert=10m;$

$\vert\overrightarrow{x}\vert=5m;$

$\overrightarrow{k}\overrightarrow{x}=\vert\overrightarrow{k}\vert\vert\overrightarrow{x}\vert cos50^o;$

$\overrightarrow{k}\overrightarrow{x}=10m\sdot5m\sdot0.6428=32.14;$

Answer: $\overrightarrow{k}\overrightarrow{x}=32.14.$