Home
Class 8
PHYSICS
A pencil is tied to one end of a string ...

A pencil is tied to one end of a string of length 5 cm and the other is fixed to a nail. If the time taken to draw a half circle and a full circle, with the pencil is 2 and 4 seconds, respectively, find the speed and velocity pecil
(a) to draw half circle is drawn.
(b) when full circle is drawn

Text Solution

Verified by Experts

(a) Distance covered to draw half circle, `s = pir`
Displacement `=2r = 2xx5=10cm`
Time taken = 2s
`:.` Speed `=("Distance")/("Time")=(5pi)/(2)cm s^(-1)`
Velocity `=("Displacement")/("Time")=(10)/(2)=5 cm s^(-1)`
(b) Distance covered to draw full circle `=2pi xx 5=10pi cms^(-1)`
Displacement=0
Time taken = 4s
Speed `=("Distance")/("time")=(10pi)/(4)=(5pi)/(2) cm s^(-)`
Velocity=0
Promotional Banner

Similar Questions

Explore conceptually related problems

A pencil is tied to one end of a string of length 5 cm and the other is fixed to a nail. If the time taken to draw a half circle and a full circle, with the pencil is 2 and 4 4 seconds, respectively, find the speed and velocity pecil (a) to draw half circle is drawn. (b) when full circle is drawn

A sphere of mass m is tied to end of a string of length l and rotated through the other end along a horizontal circular path with speed v . The work done in full horizontal circle is

A stone tied to the end of a string of length 50 cm is whirled in a horizontal circle with a constant speed . IF the stone makes 40 revolutions in 20 s, then the speed of the stone along the circle is

A stone of mass 0.2 kg is tied to one end of a string of length 80cm Holding the other end, the stone is wirled into a vertical circle. What is the minimum speed of the stone at the lowest point so that it just completes the circle What is the tension in the string at the lowest point of the circular path ? . (g =10^(-2)) .

If a bodyof mass 1000 gm is tied to free end of string of length 100 cm and whirled in a horizontal circle in a second, then the tecsion in the string will be

A stone of mass 0.2 kg is tied to one end of a string of length 80 cm. Holding the other and, the stone is whiled into a vertical circle. The minimum speed of the stone and tension at the lowest point of circular path so that it just comletes the circle are

Two circles are touches internally and their radii are 4 cm and 6 cm respectively. Find the largest chord drawn in the outer circle.

A horse is tied to a rope of length 5 cm and the other end of the rope is tied to a pole. Find the displacement and the distance travelled by the horse in the following cases (i) When the horse makes half revolution along a circular path. (ii) When it makes one full revolution (iii) When it makes (3)/(4) th of the revolution.

A block is tied to one end of a light string of length 1 whose other end is fixed to a rigid support. The block is given a speed of sqrt(7gl//2) from the lowermost position. Find the height and speed at which the block leaves the circle. Also find the maximum height to which it rises finally.