An automobile travels South 130 miles in 2.5hours and then travels West 150 miles in 3.5hours. What is the average speed and velocity ofthe trip?

Respuesta :

Given,

The distance travelled by automobile to the south, d₁=130 miles

The time it takes to cover d₁, t₁=2.5 hr

The distance travelled by automobile to the north, d₂=150 miles

The time it takes to cover d₂, t₂=3.5 hr

In the diagram, D is the total displacement of the automobile.

From Pythagoras theorem,

[tex]\begin{gathered} D=\sqrt[]{150^2+130^2} \\ =198.5\text{ miles} \end{gathered}[/tex]

The average speed is defined as the ratio of the total distance to the total time duration.

Thus the average speed of the given automobile is given by,

[tex]s=\frac{d_1+d_2}{t_1+t_2}[/tex]

on substituting the known values,

[tex]\begin{gathered} s=\frac{130+150}{2.5+3.5} \\ =46.67\text{ miles/hr} \end{gathered}[/tex]

Thus the average speed of the automobile is 46.67 miles/hr

The velocity is given by the ratio of the displacement to the time duration.

Thus the velocity of the automobile is given by,

[tex]v=\frac{D}{t_1+t_2}[/tex]

On substituting the known values,

[tex]\begin{gathered} v=\frac{198.5}{2.5+3.5} \\ =33.08\text{ miles/hr} \end{gathered}[/tex]

Thus the velocity of the automobile is 33.08 miles/hr

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