Question

A boy travels 7km towards north, and then he turns to right and he travels another 5km before coming to rest.calculate(i)total distance travelled (i)total displacement

Answer 1

Answer:

1. 7+5=12km    2.$\sqrt{} 7^{2}+5^{2}$=$\sqrt{74}$km

Explanation:

distance= 7+5=12 actually travelled

displacement=shortest possible distance

                         by phythagoras thereom

                        =$\sqrt{74}$

         

Answer 2

(i) Total distance travelled = 12 km.

(ii) Total displacement = 8.6 km

Solution :

Here let the starting point of boy be A then he travels 7 km towards north let that point be B. Then he travels to the right 5 km.

So,

⇒ Total distance = AB + BC

⇒ Total distance = 7 + 5

⇒ Total distance = 12 km.

∴ Total distance travelled = 12 km (i)

Now here body travels A to B (7 km) & B to C(5 km).

So, displacement = AC

✪ Using Pythagoras theorem :

✪ AC² = AB² + BC²

⇒ AC² = 7² + 5²

⇒ AC² = 49 + 25

⇒ AC = √74

⇒ AC = 8.6 km

∴ Total displacement = 8.6 km (ii)