# A long hand of a clock measures 28 cm. find the distance & displacement of the long hand from 4.00 pm to 5.30 pm .

2
Log in to add a comment

Log in to add a comment

first find the cicumference of the clock by the formula

C = 2 pi r

C = 2 x 22/7 x 28

C = 2 x 22 x 4

C = 44 x 4

C = 176

now make 12 divisions of the received radius by dividing 176/12

one div = 14.6

for 4 pm to 5:30

= 14.6 x 1.5

= distance=

= displacement =

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

See the diagram.

the long hand AB of the clock has two ends. One end A is fixed at the center of the circle in which the other end B of the hand rotates.

The radius R of the circle in which the tip of the long hand moves = length of the hand.

R = 28 cm.

At 4 pm and at 5:30 pm the long minutes hand of the clock is in positions AB and AB'. BAB' is a straight line.

The long hand (minutes hand) moves 360 deg. in 1 hour. So in one and half hours, it rotates 360° * 1.5 = 540° or 3 π radians.

*The angular displacement* θ of the clock hand

= angle BAB' =* 180 degrees = π radians *

*The total distance traveled by the tip of the hand B*

= 1.50 * perimeter of the circle (as B makes 1 complete revolution and 1/2 revolution)

= 1.50 * 2 π R

= 3 * 22/7 * 28 cm

* = 264 cm*

*The net displacement traveled by the tip of the hand B*

= 1/2 * perimeter of the circle (as B moves from 0 to 6).

= 1/2 * 2 π R

= 22/ 7 * 28 cm

* = 88 cm*

the long hand AB of the clock has two ends. One end A is fixed at the center of the circle in which the other end B of the hand rotates.

The radius R of the circle in which the tip of the long hand moves = length of the hand.

R = 28 cm.

At 4 pm and at 5:30 pm the long minutes hand of the clock is in positions AB and AB'. BAB' is a straight line.

The long hand (minutes hand) moves 360 deg. in 1 hour. So in one and half hours, it rotates 360° * 1.5 = 540° or 3 π radians.

= angle BAB' =

= 1.50 * perimeter of the circle (as B makes 1 complete revolution and 1/2 revolution)

= 1.50 * 2 π R

= 3 * 22/7 * 28 cm

= 1/2 * perimeter of the circle (as B moves from 0 to 6).

= 1/2 * 2 π R

= 22/ 7 * 28 cm