Home
Class 12
PHYSICS
The length of a seconds hand in watch is...

The length of a seconds hand in watch is `1 cm.` The change in velocity of its tip in `15 s` is

A

`(pi)/(15) cm//s`

B

`(pi)/(15sqrt(2)) cm//s`

C

`(pi)/(sqrt(15)) cm//s`

D

`(pi)/(sqrt(2)) cm//s`

Text Solution

Verified by Experts

The correct Answer is:
B
`v=|vecv|=(2pi)/(60)(1)=(pi)/(30) cm//s.` In 15 s, the radius vector and `vecv` rotates through an anlge `theta=90^(@).` Therefore, the angle between `vecv_(2) and -vecv_(1)` is `180^(@)-theta = 90^(@)." "therefore|Delta vecv|^(2)=|vecv_(2)-vecv_(1)|^(2)=|vecv_(2)+(-vecv_(1))|^(2)=2v^(2) cos (180-theta)=2v^(2) cos (180- theta)=2v^(2)(1-cos theta)=2v^(2)(2 sin^(2)""(theta)/(2)).`
`therefore" "|Delta vecv|=2v sin ""(theta)/(2).`
Promotional Banner

Topper's Solved these Questions

  • MULTIPLE CHOICE QUESTIONS

    NAVNEET PUBLICATION - MAHARASHTRA BOARD|Exercise Gravitation|8 Videos

  • MULTIPLE CHOICE QUESTIONS

    NAVNEET PUBLICATION - MAHARASHTRA BOARD|Exercise Rotational Motion|7 Videos

  • MODEL QUESTION PAPER FOR PRACTICE

    NAVNEET PUBLICATION - MAHARASHTRA BOARD|Exercise SECTION-D|5 Videos

  • QUESTION BANK 2021

    NAVNEET PUBLICATION - MAHARASHTRA BOARD|Exercise Semiconductors Devices (Long Answer ( LA) ( 4 marks Each) )|3 Videos

Similar Questions

Explore conceptually related problems

The length of second's hand in watch is 1 cm . The change in Velocity of its tip in 15 seconds is

The angular speed of second hand in a watch is

If the length of second s hand in a clock is 4 cm,the angular velocity and linear velocity of the tip is

The angular velocity of the seconds hand in a watch is

If the length of second's hand of a clock is 10 cm, the speed of its dip (in cm s^(-1) ) is nearly

The angular of the second hand of a watch is 1 cm . What is the velocity of a geostationary satellite is

If the length of the second's hand in a stop clock is 3 cm the angular velocity and linear velocity of the tip is