Question

A displacement vector r has a magnitude of 25m and makes an angle of 210° with the x-axis. It's y-component is

Answer 1

A displacement vector r has magnitude of 25m and makes an angle of 210° with x-axis as shown in figure.

so, it makes an angle 30° with negative part of x-axis.

then, in vector form we can write displacement vector $\vec{r}=-|r|cos30^{\circ}\hat{i}-|r|sin30^{\circ}\hat{j}$

so, it's y - component = -|r|sin30°

= -25 × 1/2 = -12.5 m [ negative sign indicates that negative part of y-axis ]

hence, magnitude of y - component = 12.5m

Answer 2

Explanation:

Answer; 12.5j cap

A displacement vector r has magnitude of 25m and makes an angle of 210° with x-axis as shown in figure.

so, it makes an angle 30° with negative part of x-axis.

then, in vector form we can write displacement vector \vec{r}=-|r|cos30^{\circ}\hat{i}-|r|sin30\hat{j}

r

=−∣r∣cos30

∘

i

^

−∣r∣sin30

∘

j

^

so, it's y - component = -|r|sin30°

Always y axis will be j cap

We have to find the y axis component so we have to take sin thetha

= -25 × 1/2 = -12.5 m [ negative sign indicates that negative part of y-axis ]

hence, magnitude of y - component = 12.5j cap