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A body is executing S.H.M. When the displacements from the mean position are 4cm and 5 cm, the corresponding velocities of the body are 10 cm per sec and 8 cm per sec. Then the time period of the body is
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- 2π sec
- π/2 sec
- π sec
- (3π/2) sec
Correct Option: C
For S.H.M., Velocity,
v = ω √a² - x² at displacement x.
⇒ 10 = ω √a² - 16 ..........(1)
and 8 = ω √a² - 25 ..........(2)
| Dividing , | = | = | ||||
| 42 | a2 - 25 | 16 |
or , 16a2 - 256 = 25a2 - 625 ⇒ 9a2 = 369
| ∴ a2 = | ||
| 9 |
Putting this value in equation (2) mentioned above,
| 10 = ω √{ (369 / 9) - 16 } ⇒ 10 = ω | ![]() | |
| 9 |
| or , ω = | = 2 radian / sec | |
| 15 |
| Time period = | = | = π sec | ||
| ω | 2 |
