Question

To a motorist travelling due North at 50km/hr, the wind appears to come from North West at 60mk/hr. Find the true velocity of the wind.​

Answer 1

Answer:43.1 km/h

Explanation:

Suppose velocity of motorist
`\vec{v_1}=50\hat{j}`

The appeared velocity of wind or resultant velocity is
`\vec{v_r}=60[\hat{i}\cdot (1)/(√(2))+\hat{j}\cdot (1)/(√(2))]`

Suppose the true velocity of wind is
`v_2`

so,
`\vec{v_1}+\vec{v_2}=\vec{v_r}`

`\vec{v_2}=(60)/(√(2))\hat{i}+((60)/(√(2))-50)\hat{j}\\\vec{v_2}=42.42\hat{i}-7.57\hat{j}\\absolute\ velocity=√(42.42^2+(-7.57)2)=43.09\approx 43.1\ km/h`