# Simple question of understanding projectile motion

• ali2coolwitu
In summary: Therefore, the vertical acceleration is 9.8m/s^2, but there is no acceleration in the horizontal direction. This means that the horizontal velocity remains constant throughout the motion, resulting in zero horizontal acceleration.
ali2coolwitu
A projectile is fired at some angle theta to the horizontal with some initial speed vi, and air resistance is neglected. Which statements about the projectile are true? (Select all that apply.)
()The projectile is a freely falling body.
()Vertical acceleration is 9.8 m/s2, upward.
()Vertical acceleration is 9.8 m/s2, downward.
()Vertical acceleration depends on theta.
()Horizontal acceleration depends on vi.
()Horizontal acceleration is zero.
()Horizontal acceleration depends on theta.

Trying to understand key concepts here to this question. Any help appreciated. Thank you!

Last edited:
ali2coolwitu said:
A projectile is fired at some angle theta to the horizontal with some initial speed vi, and air resistance is neglected. Which statements about the projectile are true? (Select all that apply.)
()The projectile is a freely falling body.
()Vertical acceleration is 9.8 m/s2, upward.
()Vertical acceleration is 9.8 m/s2, downward.
()Vertical acceleration depends on .
()Horizontal acceleration depends on vi.
()Horizontal acceleration is zero.
()Horizontal acceleration depends on .

Trying to understand key concepts here to this question. Any help appreciated. Thank you!

Depends on what? Is it angle? What answers do you think are true?

This is very simple. Dont know why i posted it. Projectile motion defined by zero horizontal velocity, acceleration downwards, and freely falling. Sorry too easy guys!

Not zero horizontal velocity, zero horizontal acceleration. There is a difference.

Casey

hii all
but why horizontal acceleration is zero?

physicskeeda said:
hii all
but why horizontal acceleration is zero?

Because there is no force acting in the horizontal direction.

The only force here is the force of gravity and that is always vertically downwards.

## 1. What is projectile motion?

Projectile motion is the motion of an object in the air that is subject to the force of gravity. It is a combination of horizontal and vertical motion, where the object moves in a curved path called a parabola.

## 2. What factors affect projectile motion?

The factors that affect projectile motion include the initial speed of the object, the angle at which it is thrown, the force of gravity, and air resistance.

## 3. What is the formula for calculating projectile motion?

The formula for calculating projectile motion is:
Horizontal displacement (x) = initial velocity (V0) x time (t) x cosine of the angle (θ)
Vertical displacement (y) = initial velocity (V0) x time (t) x sine of the angle (θ) - (1/2) x acceleration due to gravity (g) x time (t)^2

## 4. What is the difference between horizontal and vertical velocity in projectile motion?

Horizontal velocity is the component of velocity in the horizontal direction, while vertical velocity is the component of velocity in the vertical direction. In projectile motion, the horizontal velocity remains constant, while the vertical velocity changes due to the force of gravity.

## 5. How does the angle of projection affect the range of a projectile?

The angle of projection affects the range of a projectile by determining the horizontal and vertical components of velocity. A larger angle will result in a greater vertical component, causing the object to travel higher and have a shorter horizontal distance. A smaller angle will result in a smaller vertical component and a longer horizontal distance.

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