Question
A barometer kept in an elevator reads 76cm when it is at rest. If the elevator goes up with increasing speed, the reading will be:
- zero.
- 76cm.
- < 76cm.
- > 76cm.
✓
Answer
- < 76cm.
Explanation:
If the elevator goes up at an increasing speed, then the effective value of g increases.
We know:
P = ρgh.
So, h will have a lesser value for the same value of P if g increases.
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