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Angle Made by Projectile with Horizontal at Given Time

If xx and yy coordinates of a projectile as a function of time (tt) are given as 24t24t and 43.6t4.9t243.6t - 4.9t^2, respectively, then the angle (in degrees) made by the projectile with horizontal when t=2 st = 2\text{ s} is ________.

Options

A

60

B

45

Correct
C

30

D

75

Topics & Concepts

Step-by-Step Solution

To find the angle made by the velocity vector of the projectile with the horizontal at t=2 st = 2\text{ s}, we first calculate the horizontal and vertical components of the velocity as functions of time tt.

The position coordinates of the projectile are given as: x(t)=24tx(t) = 24t y(t)=43.6t4.9t2y(t) = 43.6t - 4.9t^2

Differentiating x(t)x(t) and y(t)y(t) with respect to time tt, we obtain the velocity components:

  1. Horizontal velocity component (vxv_x): vx=dxdt=24 m/sv_x = \frac{dx}{dt} = 24\text{ m/s}

  2. Vertical velocity component (vyv_y): vy=dydt=43.69.8t m/sv_y = \frac{dy}{dt} = 43.6 - 9.8t\text{ m/s}

At t=2 st = 2\text{ s}, substituting t=2t = 2 into the velocity expressions yields: vx=24 m/sv_x = 24\text{ m/s} vy=43.69.8(2)=43.619.6=24 m/sv_y = 43.6 - 9.8(2) = 43.6 - 19.6 = 24\text{ m/s}

The angle θ\theta made by the projectile's velocity vector with the horizontal is given by: tanθ=vyvx\tan\theta = \frac{v_y}{v_x}

Substituting the values of vxv_x and vyv_y: tanθ=2424=1\tan\theta = \frac{24}{24} = 1

θ=tan1(1)=45\theta = \tan^{-1}(1) = 45^\circ

Thus, the angle made by the projectile with the horizontal at t=2 st = 2\text{ s} is 4545^\circ.

Angle Made by Projectile with Horizontal at Given Time | Physics PYQ Solution - JEE Challenger