Calculus Based Questions - NEET Physics Questions
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Calculus Based Questions

Question 21: easy

A particle moves along a straight line with velocity given by v = (6 – 3t) where v is in m/s and t in seconds. Determine when the particle returns to its starting point.

1. 4 s
2. 2 s
3. 3 s
4. 5 s
View Answer

Displacement is \(s = \int v \, dt = 6t - 1.5t^2\). To return to the starting point, \(s = 0 \implies 6t - 1.5t^2 = 0 \implies t = 4\text{ s}\).

Question 22: easy

A particle begins to move along straight line where the acceleration \( (a) \) of the particle varies with displacement \( (x) \) according to relation, \( a = 5x \), then velocity of the particle varies with displacement as

1. \( x^{1/2} \)
2. \( x^1 \)
3. \( x^{1/3} \)
4. \( x^{3/4} \)
View Answer

Using \( a = v \frac{dv}{dx} \), we write \( v \frac{dv}{dx} = 5x \). Integrating both sides, \( \int v \, dv = \int 5x \, dx ⇒ \frac{v^2}{2} = \frac{5x^2}{2} + C \). Assuming the particle starts from rest, \( v^2 \propto x^2 ⇒ v \propto x^1 \).

Question 23: easy

A particle moves along a straight line with velocity given by \( v = (6 – 3t) \) where \( v \) is in \( \text{m/s} \) and \( t \) in seconds. Determine when the particle returns to its starting point.

1. \( 4\text{ s} \)
2. \( 2\text{ s} \)
3. \( 3\text{ s} \)
4. \( 5\text{ s} \)
View Answer

Displacement is \( S = \int v \, dt = \int_0^t (6 - 3t) \, dt = 6t - 1.5t^2 \). Returning to the starting point means \( S = 0 ⇒ 6t - 1.5t^2 = 0 ⇒ t = 4\text{ s} \).