- #1
Ry122
- 563
- 2
a ball is fired from a cannon at an angle of 40 degrees to the horizontal and it travels 300m before hitting the side of a cliff which is 10 meters higher than the cannons position.
Determine the initial velocity.
The ball has a negative velocity when it hits the cliff.
My attempt:
Where v = the balls initial velocity
y component of velocity = -9.81t + Vsin40
integrate this and get
y position = .5*-9.8t^2 + vsin40t
x component of velocity = vcos40
integrate this and get
x position = vcos40tUsing the expression for x velocity, solve for t at 300m in the x direction and get the expression
t=300/vcos40
Sub this into the expression for the y position above and solve for v.I'm unsure if this is the correct way to go about doing this. The velocity I ended up with is 42.7124ms^-1 which seems a bit slow for the distance it covers.
Determine the initial velocity.
The ball has a negative velocity when it hits the cliff.
My attempt:
Where v = the balls initial velocity
y component of velocity = -9.81t + Vsin40
integrate this and get
y position = .5*-9.8t^2 + vsin40t
x component of velocity = vcos40
integrate this and get
x position = vcos40tUsing the expression for x velocity, solve for t at 300m in the x direction and get the expression
t=300/vcos40
Sub this into the expression for the y position above and solve for v.I'm unsure if this is the correct way to go about doing this. The velocity I ended up with is 42.7124ms^-1 which seems a bit slow for the distance it covers.