A projectile is fired with an initial muzzle speed 190 m/s at an angle 60 from a position 5 meters above the ground level.

Find the horizontal displacement from the firing position to the point of impact.

I know that y=vsin(60)t-.5gt^2 and x=vcos(60)t. but I keep getting wrong answer.

so, what do you get?

Try plugging in you numbers here and see whether it is the same. The range is

R = v^2/g sin2θ

But does the range equation still work if the projectile starts 5 feet off the ground.

To find the horizontal displacement from the firing position to the point of impact, you will need to use the equations for projectile motion. However, it looks like you might be confusing the variables in your calculations.

Let's break down the problem step by step to ensure that we are using the correct formulas.

1. Determine the initial velocity components:
The initial muzzle speed is given as 190 m/s, and the angle of projection is 60 degrees. To find the initial velocity components (Vx and Vy), you can use trigonometry.

Vx = V * cosθ
Vx = 190 * cos(60)
Vx = 190 * 0.5
Vx = 95 m/s

Vy = V * sinθ
Vy = 190 * sin(60)
Vy = 190 * (√3/2)
Vy ≈ 164.9 m/s

2. Find the total time of flight:
The time of flight is the total time it takes for the projectile to land. The vertical motion of the projectile can be used to find the time of flight.

y = Vy * t - 0.5 * g * t^2
Since the projectile starts and ends at the same vertical position (5 meters above the ground level), we can set y = 0 and solve for t.

0 = 164.9t - 0.5 * 9.8 * t^2
0 = 164.9t - 4.9t^2

To solve the quadratic equation, you can use factoring, the quadratic formula, or any other preferred method. By solving the equation, you will find that there are two solutions: t = 0 and t ≈ 33.7 seconds. We discard t = 0 since it doesn't provide useful information in this context.

Hence, the time of flight is approximately 33.7 seconds.

3. Calculate the horizontal displacement:
Using the horizontal equation of motion, we can calculate the horizontal displacement (x) from the firing position to the point of impact.

x = Vx * t
x = 95 m/s * 33.7 s
x ≈ 3201.5 meters

Therefore, the horizontal displacement from the firing position to the point of impact is approximately 3201.5 meters.

Make sure to double-check your calculations, and pay attention to units and significant figures.