Projectile prediction (1 Viewer)

[mazza_728]

we're trying to calculate where a projectile lands after rolling of a 1m long ramp set up at 10 degrees, across a desk and finally off the .87 m high desk somewhere on the floor.. we're trying to calculate that somewhere but its not working, and our numb teacher doesnt help at all. by our calculations it should land 0.135 m away, thats 13.5 cm and in practice does not make any sense.. if anyone understands wat im talking about canu please give it a go cause its just not working for me..

 

[freaking_out]

what dot point were u trying to cover?

 

[Shoey]

Need initial velocity of projectile, unless that ramp was set up at -10 degrees.

 

[Excalibur]

so it like rolls down the table, which is inclined at -10 degrees as shoey said then off the end (which is 0.87m high). I see no reason y 13.5 cm is unreasonable answer. Try it roll something off a desk, with no initial v it ain't gonna go lik 10m.

 

[jims]

u have to use a stop watch to time how long it takes to run along the table.
lets pretend it took 1s to travel that 1m so it was travelling at 1m/s when it left the table.
now at t = 0s:
v(y) = 0 m/s
v(x) = 1 m/s

dy = ut + (1/2)at^2 = (1/2)at^2 since u = 0

from your measurements, dy = 0.87m

using that to find t from the above equation
t = sqrt (2*0.87/9.8) = 0.42s

so dx = ut = 1*0.42 = 0.42m