Question

The minute hand of a clock is 7cm long.Calculate the distance covered and the displacement of minute hand of the clock from 9.00A.M to 9.30 A.M.

Answer 1

Given:

• The minute hand of the clock = 7cm

To find:

• Distance covered at 9 : 00 A.M - 9 : 30 A.M
• Displacement 9:00 A.M - 9:30 A.M

Solution:

The time between them =

When the minute hand shows the time from 9.00 am to 9.30 am, then it has covered a distance equal to half the circumference of the circle of radius 7 cm.

Distance covered = circumference/2

Hence, the distance (d) covered by the minute hand is

d = 2πr/2 = πr = 22/7 × 7= 22 cm

___________________________

Now,

Refer the attachment for diagram and to understand

Displacement = 2(radius)

Displacement = 2(7)

Displacement = 14cm

Hence, distance travelled = 1260cm & displacement = 14cm

Answer 2

Answer:

Distance = 21.98 cm

Displacement = 14 cm

Explanation:

Given :

• Length of the minute hand = radius = 7 cm

• Minute hand moves from 9.00 Am to 9.30 Am

To find :

• Distance covered by the minute hand

• Displacement of the minute hand

At it covers from 9 to 9.30 the minute hand will move from 12 on the clock to 6 on the clock which is equal to half of the Circumference of the circle

Circumference = 2×3.14×7

Circumference = 6.28×7

Circumference = 43.96 cm

Distance covered = 43.96/2 = 21.98 cm

The distance covered is equal to 21.98

The Displacement will be equal to diameter as it is at opposite point of initial point

Displacement = 2×7 = 14 cm