Question

A body of mass m moves in a horizontal circle of radius r at constant speed v. Which pair of values correctly gives (i) the work done by the centripetal force, (ii) the change in linear momentum of the body, when it moves from X to Y (where XY is a diameter)?

(i) Work done (ii) Charge in linear momentum

• A. 2mv²2mv
• B. pmv²2 mv
• C. 0 0
• D. 0 2 mv

Answer 1

Answer: (D)

0 2 mv

Answer 2

Q $\overrightarrow { \mathrm { p } } _ { 1 } + \overrightarrow { \mathrm { p } } _ { 2 } + \overrightarrow { \mathrm { p } } _ { 3 }$ = 0

\ $\overrightarrow { \mathrm { p } } _ { 3 } = - \left( \overrightarrow { \mathrm { p } } _ { 1 } + \overrightarrow { \mathrm { p } } _ { 2 } \right)$ = $- ( p \hat { i } + \sqrt { 3 } p \hat { j } )$

̃ p₃ = $\mathrm { p } \sqrt { 1 + ( \sqrt { 3 } ) ^ { 2 } }$ = 2p