NEET Physics: Kinematics questions with solutions

Q1. Displacement of a body is given by \( x= \) \( \mathbf{5}+\mathbf{3} t+\mathbf{2} t^{2} . \) The value instantaneous acceleration is:

1. 4 units
2. 6 units
3. 5 units
4. 2 units

Answer: 2 units

For x = 5 + 3t + 2t^2, velocity is dx/dt = 3 + 4t. Differentiating again gives acceleration a = d²x/dt² = 4, so the stated correct option appears inconsistent with the formula.

Q2. \( k g m s^{-1} \) is the Sl unit of

1. Impulse
2. Force
3. Angular velocity
4. None of these

Answer: Impulse

The unit kg·m·s⁻¹ is the same as momentum. Impulse equals change in momentum, so it has the same SI unit.

Q3. The velocity-time graph for a body with non-uniform motion (assume non- constant acceleration) is a:

1. straight line making some angle with the positive \( x \) axis.
2. straight line parallel to x-axis.
3. straight line parallel to y-axis
4. curved line

Answer: curved line

On a velocity-time graph, the slope represents acceleration. If acceleration is non-constant, the slope must change from point to point, so the graph cannot be a straight line. Therefore, it must be a curved line.