Practice NEET Ground to Ground Projectile Questions
Question 1:
moderate
The height y and the distance x along the horizontal plane of a projectile on a certain planet (with no surrounding atmosphere) are given by y = (8t – 5t²) meter and x = 6t meter, where t is in second. The velocity with which the projectile is projected is :
Given:
\[
y = 8t - 5t^2 \quad \text{and} \quad x = 6t
\]
To find the initial velocity, we calculate the horizontal and vertical components of velocity:
The maximum height reached by projectile is 4 m. The horizontal range is 12m. The velocity of projection in ms–¹ is : (g is acceleration due to gravity) :
A particle is projected at 60° to the horizontal with a kinetic energy K. The kinetic energy at the highest point is :
At the highest point of its trajectory, the vertical component of the velocity becomes zero, while the horizontal component remains unchanged.
Initial kinetic energy \( K \) is given by:
\[
K = \frac{1}{2} m u^2
\]
At the highest point, only the horizontal component of the velocity \( u \cos 60^\circ \) remains. Therefore, the kinetic energy at the highest point is due to this horizontal velocity:
\[
K_{\text{highest}} = \frac{1}{2} m (u \cos 60^\circ)^2
\]
Since \( \cos 60^\circ = \frac{1}{2} \):
\[
K_{\text{highest}} = \frac{1}{2} m \left(\frac{u}{2}\right)^2 = \frac{1}{4} \times \frac{1}{2} m u^2 = \frac{K}{2}
\]
Thus, the kinetic energy at the highest point is \( \frac{K}{2} \).
If a body A of mass M is thrown with velocity v at an angle 30° to the horizontal and another body B of same mass is thrown with same speed at an angle of 60° to the horizontal, the ratio of range of A and B will be :
Three projectiles A, B and C are thrown from the same point in the same plane. Their trajectories are shown in the figure. Which of the following statement is true ?
As maximum height is same is all three they will have same vertical speed.
Range of C is maximum so its horizontal speed is maximum.