Question

For a certain body, the velocity-time graph is shown in the figure. The ratio of applied forces for intervals AB and BC is

• A. $+ \frac { 1 } { 2 }$
• B. $- \frac { 1 } { 2 }$
• C. $+ \frac { 1 } { 3 }$
• D. $- \frac { 1 } { 3 }$

Answer 1

Answer: (D)

$- \frac { 1 } { 3 }$

Answer 2

Ratio of applied force = Ratio of acceleration

= $\frac { a _ { \mathrm { AB } } } { \mathrm { a } _ { \mathrm { BC } } } = \frac { \tan 30 } { \tan ( 120 ) } = \frac { 1 / \sqrt { 3 } } { - \sqrt { 3 } }$ = $- 1 / 3$