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A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 ms–1 to 20 ms–1 while passing through a distance 135 m in t second. The value of t is:
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- 10
- 1.8
- 12
- 9
Correct Option: D
Initial velocity, u = 10 ms–1
Final velocity, v = 20 ms–1
Distance, s = 135 m
Let, acceleration = a
Using the formula, v² = u² + 2as
| a = | |
| 2s |
| = | = | ||
| 2 × 135 | 2 × 135 |
| a = | = | = | ms-2 | |||
| 2 × 135 | 135 | 9 |
= Now, using the relation, v = u + at
| t = | = | = | × 9sec = 9s. | |||
| a | 10/9 | 10 |
