Question

A particle moves in a circle with O as centre and AO = OB = 5cm, as radius. It starts from A. Calculate (a) The distance covered, and (b) The displacement when it reaches B.

Answer 1

(A). (Assuming that it goes from point A and return to point A by covering its circumference)
Circumference of a circle= 2πr ( where r is the radius)
= 2×22÷7×5
= 31.4285714
(B). ( Assuming that point B is on the opposite side of point A)
if A and B are on the opposite side, then the displacement =the diameter of the circle
diameter=AB=2r
AB= 2×OB
AB=2×5
AB=10,. the displacement is 10cm

Answer 2

Answer:

Distance travelled by particle is 15.7 cm and displacement of the particle is 10 cm.

Explanation:

• Distance covered by a particle is total length travelled by particle between any two given points.
• Displacement of particle is the shortest distance between the any two given points.

Given that :

• Particle start from A and ends at B

To find :

• Distance and displacement when it reaches B.

Solution :

• Let A particle moves on circular track with centre as O. It starts from point A and reaches point B.
• Since, the radius of circle is 5 cm and AB form the diameter of the circle.
• Distance travelled by particle from A to B is
• d = πr = 3.14 x 5 cm = 15.7 cm
• Displacement of the particle from A to B is
• AB = (AO + OB) = (5 + 5) cm = 10cm.
• Hence, distance travelled by particle is 15.7 cm and displacement of the particle is 10 cm.