# How Do You Solve These Projectile Motion Problems?

• 7up
In summary, Romeo is chucking pebbles gently up to Juliet's window, and he wants the pebbles to hit the window with only a horizontal component of velocity. he is standing at the edge of a rose garden 8.0 meters below her windows and 9.0 meters from the base of the wall. How fast are the pebbles going when they hit her window? If you could please explain how to the get the answer so that even a newbie like me can understand, I would be so grateful.
7up
Hey guys, I am taking an AP physics course and I'm fairly new to this challenging physics. If you could please explain how to the get the answer so that even a newbie like me can understand, I would be so grateful.

1. Romeo is chucking pebbles gently up to Juliet's window, and he wants the pebbles to hit the window with only a horizontal component of velocity. he is standing at the edge of a rose garden 8.0 meters below her windows and 9.0 meters from the base of the wall. How fast are the pebbles going when they hit her window?

2. A ball thrown horizontally at 22.2. m/s from the roof of a building lands 36.0 meters from the base of the building? What is it's height?

3. A shot-putter throws the shot with an initial speed of 14 m/s at a 40 degree angle to the horizontal. Calculate the horizontal distance traveled by the shot if it leaves the athlete's hand at a height of 2.2 m above the ground?

4. AN athlete executing a long jump leaves the ground at a 30 degree angle and travels 7.8 meters. What was the takeoff speed? If this speed were increased by 5 percent, how much longer would the jump be by?

5. A hunter aims directly at a level target 120 m away. If the bullet leaves the gun at a speed of 250 m/s, by how much will it miss the target. At what angle should the gun be aimed so the target will be hit?

6. A projectile is fired with an initial speed of 75.2 m/s at an angle of 34.5 above the horizontal on a long flat firing range. Determine the maximum height reached by the projectile, the total time in the air, the total horizontal distance covered (the range) and the velocity of the projectile 1.5 s after firing.

Hi 7up,

Forum rules state you must show some work in order to get help. What are your thoughts on the first question? Can you elaborate on where you are having trouble? Take a look at this site and see if it helps you out a bit: http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html Click on Mechanics, then Velocity and Acceleration, then Trajectories to get to the information more specific to your homework.

Last edited:
hmm..projectile motion...
i advise you to learna and master the basics of the subject first before trying to do the questions. ok let's see if you can understand the subject than these problems should not be much of a challenge.. oh and have a calculator with you while you are trying the questions. it will come in useful!
yea and i agree with hage567 that you should visit the website for help
maybe you can show us some of your attempts of the questions and then show it to uss for us to justify them. =)
(visit my blog!)

Last edited:
Mr. Survive,

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Whilst we appreciate your help here in the Homework forums, I would like to remind you of the Physics Forums Global Guidelines, which you agreed to upon registration,

Physics Forums Global Guidelines said:
On helping with questions: Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given. Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.

Note: I have deleted the complete solutions provided by new member mr.survive. As Hootenanny points out, posting complete solutions is against PF rules.

i tried to solve problem number 2 given above, and using the formula given by our professor i came up with this answer, height=12.89m.. is this correct?

given the ff. formulas:

time=SQRT of (twice the height / g )

Range=initial velocity x time

Ms. Curious said:
i tried to solve problem number 2 given above, and using the formula given by our professor i came up with this answer, height=12.89m.. is this correct?

given the ff. formulas:

time=SQRT of (twice the height / g )

Range=initial velocity x time
Looks OK to me.

## 1. What is projectile motion?

Projectile motion is the motion of an object through the air or space under the influence of gravity alone. It is a type of motion that can be observed in everyday life, such as a ball being thrown or a bullet being fired.

## 2. What are the key factors that affect projectile motion?

The key factors that affect projectile motion are the initial velocity, launch angle, and the force of gravity acting on the object. These factors determine the path and distance traveled by the object.

## 3. How is the range of a projectile calculated?

The range of a projectile is the horizontal distance it travels before hitting the ground. It can be calculated using the formula: R = (v02 * sin(2θ)) / g, where v0 is the initial velocity, θ is the launch angle, and g is the acceleration due to gravity.

## 4. Can the maximum height of a projectile be greater than its initial height?

Yes, the maximum height of a projectile can be greater than its initial height. This occurs when the launch angle is greater than 45 degrees and the initial velocity is high enough to overcome the effects of gravity.

## 5. How does air resistance affect projectile motion?

Air resistance, also known as drag, can affect projectile motion by slowing down the object and altering its trajectory. In some cases, it can cause the object to fall short of its expected range. However, for most everyday scenarios, the effect of air resistance on projectile motion is negligible.

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