Question

As shown in the figure, a particle of mass 10 kg is placed at a point A. When the particle is slightly displaced to its right, it starts moving and reaches the point B. The speed of the particle at B is x m/s. (Take g = 10 m/s²) The value of 'x' to the nearest integer is __________. [Note: Usually $h_A = 10$m and $h_B = 5$m in this problem] 

Hint:

For conservative forces like gravity, speed depends only on the change in vertical height ($\Delta h$), not the path taken.

Answer 1

Correct Answer: 10

Step 1: Use Law of Conservation of Energy: $mgh_A = mgh_B + \frac{1}{2}mv^2$.
Step 2: $v = \sqrt{2g(h_A - h_B)}$. If $\Delta h = 5\text{m}$:
Step 3: $v = \sqrt{2 \times 10 \times 5} = \sqrt{100} = 10 \text{ m/s}$.