A projectile is fired at an angle of 60° with the horizontal. If the horizontal range is 2 km, then the velocity of projection is approximately ________.

CONCEPT: 

Projectile motion: 

A kind of motion that is experienced by an object when it is projected near the Earth's surface and it moves along a curved path under the action of gravitational force.

When a particle moves in projectile motion, its velocity has two components.

1. ​​vertical component (u sinθ)
2. horizontal component (u cosθ)

• The maximum height a projectile can attain

where u is the velocity that makes an angle 'θ' with the x-axis, and g is the gravitational acceleration.

The range of flight is given by:

CALCULATION:

Given that R = 2000 m ; θ = 60°; g = 9.8 m/s2

• The range of flight is given by:

u = 150.44 m/s

So the correct answer is option 4.

Additional Information

T he time of flight of projectile is given by: 

where u is the velocity, makes an angle 'θ' with the x-axis, and g is the gravitational acceleration.

The range of flight is given by:

where u is the velocity, makes an angle 'θ' with the x-axis, and g is the gravitational acceleration.