Question

A projectile is fired on a horizontal ground. Variation of slope of its trajectory with horizontal displacement is shown (g = 10 m/s2).
Choose the CORRECT statement(s);
slope
10
- +
Angle of projection of projectile is 60°
Horizontal range of projectile is 20 m
Time of flight of projectile is 2 sec
Area under-curve gives vertical displacement of projectile​

Answer 1

Given that,

Acceleration due to gravity = 10 m/s²

Suppose, Angle of projection = 30°

Initial velocity = 20 m/s

We need to calculate the time of flight of projectile

Using formula of time of flight

$t=\dfrac{2u\sin\theta}{g}$

Where, u = initial velocity

g = acceleration due to gravity

Put the value into the formula

$\theta$ = angle of projection

$t=\dfrac{2\times20\sin30}{10}$

$t=2\ sec$

We need to calculate the horizontal range

Using formula of range

$R=\dfrac{u^2\sin2\theta}{g}$

Put the value into the formula

$R=\dfrac{20^2\times\sin2\times30}{10}$

$R=34.6\ m$

Hence, The time of flight of projectile is 2 sec.

(3) Option is correct.