Question

Ananya is travelling to visit her grandmother. First, she travels at an average speed of 12 km/h for

10 km. Then she travels at 8.0 km/h for another 1.25 h. Calculate her average speed for the entire

trip to her grandma's house.



(1) 3.20 km/h
(2) 4.40 km/h
(3) 9.60 km/h
(4) 19.2 km/h


Hurry
​

Answer 1

Answer:

Concept:

The overall distance traveled by an object in a given time interval is the average speed. The scalar quantity average speed is a scalar quantity. It has no direction and is indicated by magnitude.

Explanation:

$D=d_{1}+d_{2}, T=\tau_{1}+\tau_{2} . \\given, speed =12 Time = ? \left(T_{1}\right) Dist = d1Time =\frac{10}{12}=0.83 d_{2}= ? \begin{gathered}\text { speed }=8 \text {. km/h } \\T=1.25 \text { or } \frac{5}{4} \text { hour } \\d_{2}=8 \times \frac{5}{4}=10 \mathrm{~km} \\D=10+10=20 \mathrm{~km}, \\T=1.25+0.83=2.08 \\\text { Avg speed }=\frac{20}{2.08}=9.60\end{gathered}$

#SPJ2