Question

A body is projected from the ground with a speed 10 m/s at angle 30° with the horizontal. The height of the body after 5 seconds of its projection is (Acceleration due to gravity = 10 m/s²)

• A. 0.75 m
• B. 1 m
• C. 1.25 m
• D. 1.5 m

Hint:

In projectile motion, always resolve the velocity into horizontal and vertical components and use the kinematic equations for vertical displacement.

Answer 1

The Correct Option is B

The vertical component of velocity is given by: \[ v_y = 10 \sin 30^\circ = 5 \, \text{m/s} \] Using the equation for vertical displacement: \[ h = v_y t - \frac{1}{2} g t^2 \] Substitute the values \( v_y = 5 \, \text{m/s} \), \( g = 10 \, \text{m/s}^2 \), and \( t = 5 \, \text{s} \): \[ h = 5 \times 5 - \frac{1}{2} \times 10 \times 5^2 = 25 - 125 = -100 \, \text{m} \] The height is 1 m above the ground.