Need Help: Projectile Motion Problem

In summary, the conversation revolves around an attack on a castle with a cannon. The cannon shoots a ball at a speed of 46.1 m/s and an angle of 44.1 degrees, hitting the tyrant's chamber at the same level as the cannon's muzzle. The question is asking for the time of flight of the cannon ball, which can be calculated using the equation Y=Yi+Viy(t)-1/2gt^2. After some calculations and using the correct value for viy, the time of flight was found to be 6.756 seconds. However, the answer was marked wrong on an online homework site and the person is seeking help to determine what was done incorrectly.
  • #1
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1. Assume you are a medieval knight attacking a castle with a cannon. The ball leaves the cannon with a speed of 46.1 m/s. The barrel's angle with respect to the ground is 44.1 degree, and you make a perfect hit on the tyrant's chamber which is at the same level as the cannon's muzzle. What is the time (in s) of flight of the cannon ball?

2. Y=Yi+Viy(t)-1/2gt^23.
Viy=46.1 m/2
Y & Yi=0
Theta Angle=44.1 degree
g=9.8m/s^2

I used this equation: Y=Yi+Viy(t)-1/2gt^2
0=0+46.1cos44.1(t)-1/2gt^2
4.9t^2/4.9t=33.106t/4.9t
t=6.756s

I drew the x/y coordinate system, right angle and sin/cos to help with solving the problem.
The online homework site says my answer is wrong. Please help. What am I doing wrong? Is it the equation or my algebra?
 
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  • #2
viy is v*sinθ.
 
  • #3
Thank you! I'll try that.
 

1. What is projectile motion and how is it different from regular motion?

Projectile motion is the motion of an object that is thrown or launched into the air, moving in a curved path due to the influence of gravity. It is different from regular motion because it involves both horizontal and vertical components of motion, whereas regular motion only involves movement in one direction.

2. How do you calculate the trajectory of a projectile?

The trajectory of a projectile can be calculated using the equations of motion, taking into account the initial velocity, angle of launch, and gravitational acceleration. The horizontal and vertical components of motion can be calculated separately and then combined to determine the overall trajectory.

3. What factors affect the trajectory of a projectile?

The factors that affect the trajectory of a projectile include the initial velocity, angle of launch, air resistance, and gravitational acceleration. Other factors such as wind speed and direction can also have an impact on the trajectory of a projectile.

4. How can we use projectile motion in real life?

Projectile motion has many practical applications, such as in sports like basketball and baseball, where players need to accurately throw or hit a ball to a specific target. It is also used in military applications for calculating the trajectory of weapons and in engineering for designing and testing projectiles.

5. What are some common problems encountered in solving projectile motion?

Some common problems encountered in solving projectile motion include not taking into account air resistance, incorrect use of equations, and miscalculating the angle of launch. It is important to carefully consider all factors and use the correct equations to accurately solve projectile motion problems.

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