Projectile motion help (1 Viewer)

[yashbb]

Why do I have to solve for Vy q6 a

 

[ExtremelyBoredUser]

Why do I have to solve for Vy q6 aView attachment 32435

For q6 a, you might need to solve for Vy in order to find the time of flight for which you can use to find the range to solve the question.

R = U_x * t_time of flight

You can find time of flight through vertical velocity. Hence;

Vy = sqrt(Uy^2 + 2gs)
Vy = Uy + gt
time of flight = (Vy - Uy)/g

Now substitute that value for time of flight into the range equation and you found the answer.

Edit: I'm horrible at using latex, apologies for the thousand edits.

 

[yashbb]

For q6 a, you might need to solve for Vy in order to find the time of flight for which you can use to find the range to solve the question.

R = U_x * t_time of flight

You can find time of flight through vertical velocity. Hence;

Vy = sqrt(Uy^2 + 2gs)
Vy = Uy + gt
time of flight = (Vy - Uy)/g

Now substitute that value for time of flight into the range equation and you found the answer.

Edit: I'm horrible at using latex, apologies for the thousand edits.

Hahaha all good man I just am wondering why I can’t use Sy=Uyt+0.5at^2

 

[A1La5]

Hahaha all good man I just am wondering why I can’t use Sy=Uyt+0.5at^2

You can, it's a quadratic equation in terms of time, as we know what the vertical displacement, a (-9.8 m/s/s), and Uy are. Use the quadratic formula and filter out any negative answers given as time cannot be negative (I got ~ 12.5 seconds defining upwards as the positive direction). You then substitute the time of flight into the range equation to answer the question.

Just for reference, I solved the following equation, where the initial vertical velocity is negative as the pallet is going downwards:

 

[ExtremelyBoredUser]

Hahaha all good man I just am wondering why I can’t use Sy=Uyt+0.5at^2

Oh your original post said Vy instead of Sy. You should be able to use the Sy equation regardless as shown in the post above.

 

[yashbb]

Oh your original post said Vy instead of Sy. You should be able to use the Sy equation regardless as shown in the post above.

oh yea sorry about that, i got the answer wrong and i figure out why i can use it. THANK YOUU