Question

A car goes round circular path of radius 14km at a constant speed of 22km/hr. Find the
distance and displacement on the car at the end of 5hrs.
3) 110km, 14km 4) 110km, 14√2
1) 110km, 110km 2) 110km, 28 km​

Answer 1

Answer:

Distance covered = 110 m

Displacement = 14√2 m

Explanation:

given that,

A car goes round circular path of radius 14km at a constant speed of 22km/hr

here,. we have,

radius of a circular path = 14 km

and speed of the car = 22 km/h

distance of one revolution of the circular path = circumstance of the circular path

so,

circumstance of the path = 2πr

where,

r is the radius of the circular path.

putting the values

circumstance = 2 × 22/7 × 14

= 88 km

now,

we have speed of the car = 22 km/h

and also given that,

car on continued its motion for 5 hours

so,

total distance covered = total path length

= speed × time

= 22 × 5

= 110 km

so,

distance travelled = 110 km

now,

number of revolution in 5 hours

total distance covered/circumference of the circular path

= 110/88

= 1 total revolution and 110 - 88

= 22 km extra distance covered

and at the full revolution

displacement will zero

and for 22 km path length it will cover

(22/88 = 4 ) 1/4th path length of the circular path,

so,

the chord formed by the path length form right angle on the centre,

and length of the cord is the displacement,

so,

by the Pythagoras theorem

length of the chord = √(r² + r²)

= √(2r²)

= r√2

so,

displacement = 14√2 m

so,

___________________

Distance covered = 110 m

Displacement = 14√2 m

Answer 2

Answer:

Distance covered = 110 m

Displacement = 14√2 m

Explanation:

given that,

and speed of the car = 22 km/h

time taken = 5 hrs

radius of the circular path = 14 m

so,

distance covered = 22 × 5= 110 km

circumstance of the circular path =

2 × 22/7 × 14

= 88 m

distance travelled after one revolution = 110 - 88

= 22

= 22/88

= 1/4th of the path

displacement = r√2

= 14√2 m

so,

Distance covered = 110 m

Displacement = 14√2 m