Vaishali Gupta, Supriya Seshadri and, Shalini Bajaj Solutions for Exercise 5: Exercises

Describe an activity to demonstrate the constancy of the time period of a pendulum.

Recall and complete the concept map given below.

Raju and Arjun are both late for school. One is running, and the other is going with his father in a vehicle. Look at the distance-time graphs below and identify who is running and who is going in a vehicle.

An ant and a snail went on a running race. Their distance-time graphs are shown above. Who is faster?

The distance between the Earth and the moon is $384,400 \mathrm{km}$. It takes four days for a spacecraft to travel from the Earth to the moon. Calculate the speed of the spacecraft. (Hint: Take $1$ day = $24$ hours).

It takes light from the Sun approximately $8 \mathrm{minutes}$ to reach the Earth. The speed of light is $3\times {10}^8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ (this is $3$ followed by eight zeros). Use this data to calculate the approximate distance of the Earth from the Sun.

Kushal loves to visit his grandparents every year to spend his summer holidays with them. They live in a remote village. He takes a train, then a bus and then, walks the rest of the journey. The train travels at $60 \mathrm{km}/\mathrm{h}$ for $5$ hours, the bus travels at $40 \mathrm{km}/\mathrm{h}$ for $3$ hours and he walks at a speed of $5 \mathrm{km}/\mathrm{h}$ for $1$ hour. What is the total distance he travels from the railway station to his grandparents' house? 
 

What would be the speed required to travel the distance of two thousand kilometres in two and a half hours? Which would be the most ideal mode of travel, if cost is not a factor?