# Grade 11 Physics: Projectile Motion Calculations

• brain123
In summary, the conversation is about a Grade 11 Physics question on projectile motion calculations. The question asks for the time a bullet, shot horizontally from a gun with a speed of 325 m/s and a height of 2.0m above the ground, stays in the air. The person is unsure of which formula to use and asks for help. The solution is that the time does not depend on the horizontal velocity, only on the vertical direction. Therefore, it is a free fall problem.
brain123

## Homework Statement

Ok, well I have a Grade 11 Physics question regarding Projectile Motion Calculations. The question is: A bullet is shot horizontally from a gun. If the bullet's speed exiting the muzzle is 325 m/s and the height of the gun above the ground is 2.0m,

a) how long was the bullet in the air?

## The Attempt at a Solution

I see that a) is looking for the time. As well as, I have 325 which I assume is the velocity and 2.0m which I assume is the distance. Now this is the part I am stuck on. Which formula do I use to find Time? Sorry if my question seems stupid. I'm just in need for some help.

Thanks

Think about what the problem is asking you. Does the time it takes for the bullet to fall vertically depend on how fast it is moving horizontally?

fss said:
Think about what the problem is asking you. Does the time it takes for the bullet to fall vertically depend on how fast it is moving horizontally?

Hmm ... well I guess it would? Sorry I'm a physics noob.

nope it doesnt. it just depends on vertical direction...now do you get a clue?

It is basically a free fall problem.

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

Projectile motion is a type of motion in which an object is thrown or projected into the air and moves in a curved path under the influence of gravity. It is different from regular motion because it involves both horizontal and vertical components of motion, while regular motion only involves movement in one direction.

## 2. How do you calculate the initial velocity of a projectile?

The initial velocity of a projectile can be calculated by using the equation V0 = V*cosθ, where V is the velocity of the projectile and θ is the angle of projection.

## 3. How does air resistance affect the trajectory of a projectile?

Air resistance can affect the trajectory of a projectile by slowing it down and altering its path. This is because air resistance creates a force in the opposite direction of motion, causing the projectile to lose speed and change direction.

## 4. Can you explain the difference between range and maximum height in projectile motion?

Range refers to the horizontal distance traveled by a projectile before it hits the ground, while maximum height refers to the highest vertical position reached by the projectile. The two are related, as the maximum range is achieved when the projectile is launched at a 45-degree angle.

## 5. How do you calculate the time of flight for a projectile?

The time of flight for a projectile can be calculated using the equation t = (2*V*sinθ)/g, where V is the initial velocity, θ is the angle of projection, and g is the acceleration due to gravity. This equation assumes no air resistance and a level surface.

• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
11
Views
1K
• Introductory Physics Homework Help
Replies
19
Views
2K
• Introductory Physics Homework Help
Replies
3
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
11
Views
1K
• Introductory Physics Homework Help
Replies
39
Views
3K
• Introductory Physics Homework Help
Replies
3
Views
2K