# Projectile Motion- Horizontal Range and Time of Flight

• leah3000
In summary, a rifle is used to fire two bullets at angles of 60° and 45° above the horizontal with a speed of 200ms^1. For each bullet, the horizontal range and time of flight can be calculated using the equations v^2sin2ө/ g and 2vsinө/g. The horizontal range for the first shot is 3531m with a time of flight of 35.3 seconds, and the horizontal range for the second shot is 4077m with a time of flight of 28.8 seconds. The initial velocity, v, is equal to 200 m/s.

## Homework Statement

A rifle is used to fire two bullets. The first shot is at an angle of 60° above the horizontal and the second at an angle of 45° above the horizontal. The speed of EACH bullet as it leaves the rifle is 200ms^1. For EACH bullet calculate the horizontal range and the corresponding time of flight.

## Homework Equations

Horizontal Range: v^2sin2ө/ g

Time of Flight= 2vsinө/g

## The Attempt at a Solution

Horizontal Range for 1st shot= (200^2)sin2(60)/9.81

=3531m

Time of Flight= 2(200)sin(60)/9.81

=35.3 secs

Horizontal Range for 2nd shot= (200^2)sin2(45)/9.81

=4077m

Time of Flight= 2(200)sin(45)/9.81

= 28.8 secs

I'm not sure if I'm supposed to use the 200 as v or if I'm to calculate v somehow from the given information. Last edited:
You have used the equations correctly. I guess you are just not sure how the equations work? Maybe reading the proofs of these equations would help.

ok...i just keep thinking that since it left the rifle at 200ms^1that that would be the initial velocity, u. I wasn't too sure if I could use it in the equation as v. I thought that i some how had to calculate it but then there would be more than one unknowns when using the equatios of motion ok...i just keep thinking that since it left the rifle at 200ms^1that that would be the initial velocity, u. I wasn't too sure if I could use it in the equation as v. I thought that i some how had to calculate it but then there would be more than one unknowns when using the equations of motion v represents initial velocity, so it should be 200 m/s.

ok thank you