Need help with projectiles initial velocity using height and distance

In summary, the conversation discusses calculating the initial velocity of a home run ball that was estimated to have landed 180 meters from the home plate and reached a height of 21.3 meters. The equation u^2=v^2-2as is used, with u representing initial velocity, v representing final velocity (which is 0 in this case), s representing displacement (180 meters in this case), and a representing acceleration (in this case, the acceleration due to gravity which is -9.8 m/s^2). By plugging in the given values, the initial velocity is calculated to be 59.9 m/s. The conversation also raises questions about the use of the equation and the need to find the angle and consider
  • #1
batcave1985
7
0
home run that was estimated to have
landed 180 metres from the home plate and to have reached a
height of 21.3 metres. Calculate the initial velocity of the
ball.

u^2=v^2-2as

t=?
u=?
v=0
s=180
a=g= -9.8

u^2= √0^2-2x-9.8x180
u= 59.9 m/s


am I using the right equation for this problem. I am not sure if I have to find the angle using the height and the range of the ball to help find the initial velocity. just want to know if this is the right direction with this problem
 
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  • #2
What are u and v? What is s? And why do you not use the maximum height? Does the ball move horizontally? If so, is g the horizontal acceleration? Does not accelerate Earth the objects vertically?

ehild
 

FAQ: Need help with projectiles initial velocity using height and distance

What is the formula for calculating initial velocity in a projectile motion problem?

The formula for calculating initial velocity in a projectile motion problem is v0 = √(g * d / sin(2α)), where v0 is the initial velocity, g is the acceleration due to gravity, d is the horizontal distance traveled, and α is the launch angle.

How do I find the initial velocity if the height and distance are given?

To find the initial velocity if the height and distance are given, you can use the formula v0 = √(g * d / sin(2α)), where d is the horizontal distance traveled and α is the launch angle. You can then substitute the given values for d and α into the formula to calculate the initial velocity.

Can I use the same formula to calculate initial velocity for any projectile motion problem?

Yes, the formula v0 = √(g * d / sin(2α)) can be used to calculate initial velocity for any projectile motion problem as long as the launch angle and horizontal distance are known.

What units should be used for the values in the formula for calculating initial velocity?

The units used for the values in the formula for calculating initial velocity should be consistent. For example, if the distance is given in meters, then the acceleration due to gravity should also be given in meters per second squared (m/s²). The resulting units for initial velocity would then be meters per second (m/s).

Can I use this formula to calculate initial velocity if the projectile is launched from an elevated position?

Yes, the formula v0 = √(g * d / sin(2α)) can be used to calculate initial velocity for any projectile motion problem, regardless of the launch position. However, the height of the launch position must be taken into account when calculating the launch angle (α) for the formula. This can be done using the trigonometric function tan (tangent).

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