- #1
Robb
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Homework Statement
Homework Equations
kinematics.
a=F/m
The Attempt at a Solution
100cos(70)=342
100sin(70)=393.7
X=1/2(-9.8)t^2+100t; t=0. t=20.4
Find height, range and time of flight for projectile motion
- Thread starter Robb
- Start date
In summary, the problem involves a projectile being launched from the top of a building with an initial velocity of 100m/s at an angle of 70 degrees. The kinematic equations are used to determine the x and y components of the velocity, as well as the time of flight and the maximum height reached. However, without knowing the height of the building, the calculations are incomplete and an assumption must be made about the elevation.
kinematics.
a=F/m
100cos(70)=342
100sin(70)=393.7
X=1/2(-9.8)t^2+100t; t=0. t=20.4
- #2
SteamKing
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You might want to check the arithmetic above before going further in this calculation. Also, don't forget to indicate units.Robb said:
- #3
CWatters
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Ok so you have an equation for the initial vertical velocity. What else do you know about the motion in the vertical plane? Final velocity at the top = ? Acceleration =? What other equations of motion do you know that might be relevant?
- #4
Robb
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y component = 94
velocity at the top = 0
acceleration from g = -9.8m/s
I know my basic kinematics and a=f/m
velocity at the top = 0
acceleration from g = -9.8m/s
I know my basic kinematics and a=f/m
- #5
gneill
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The problem states that the projectile is launched from the top of a building, yet doesn't state the height of that building. So what interpretation are we to place upon the Range and Time of Flight parts? Is a symbolic answer with an assumed starting height (say h) desired, or do we consider the landing elevation to be the same as the launch elevation? Is there any point to the building?
- #6
Robb
- 225
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I assume the range to be where the projectile lands (on the ground) and the time would stop at that point as well. I guess there is no point to the building although the elevation effects time and distance traveled.
- #7
Robb
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h=[v(initial)^2*sin(theta)^2]/2g = [(100)^2(sin70)^2]/-19.6 = -450.5
Not sure how this can be negative unless it is accounting for the height of the building?
Not sure how this can be negative unless it is accounting for the height of the building?
- #8
gneill
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The g in this case is just the constant g without sign. You might try deriving the expression for the maximum height to see why this is.Robb said:
FAQ: Find height, range and time of flight for projectile motion
What is projectile motion?
Projectile motion is a type of motion where an object is thrown or projected into the air and then moves along a curved path under the influence of gravity. Examples of projectile motion include a ball being thrown, a bullet fired from a gun, or a rocket launched into space.
How do you find the height of a projectile?
The height of a projectile can be found using the equation h = h0 + v0t - 1/2gt2, where h0 is the initial height, v0 is the initial velocity, g is the acceleration due to gravity (9.8 m/s2), and t is the time.
What is the range of a projectile?
The range of a projectile is the horizontal distance it travels before hitting the ground. It can be calculated using the equation R = v0t, where v0 is the initial velocity and t is the time.
How do you find the time of flight for a projectile?
The time of flight for a projectile is the total time it takes for the object to travel from its initial position to its final position. It can be calculated using the equation t = 2v0/g, where v0 is the initial velocity and g is the acceleration due to gravity.
What factors affect the height, range, and time of flight of a projectile?
The height, range, and time of flight of a projectile are affected by the initial velocity, launch angle, and the acceleration due to gravity. The initial velocity and launch angle determine the direction and speed of the projectile, while the acceleration due to gravity affects the vertical motion of the projectile.