Question

how to caculate the speed and direction of an object when it falls off a cliff on to an another object ?

Answer 1

Is it about Projectile motion ???

Answer 2

yup,
vertical cicular motion

Answer 3

falling off a cliff at an angle requires you to use component vectors, differentiation and integration techniques

Answer 4

can u show me an example of that?

Answer 5

but the rate at which an object fall is the same
it follows -9.8 m/s^2 and that would be the acceleration due to gravity

Answer 6

ik that but im looking for the speed, which i cant find it

Answer 7

speed is irrelevant, because it is changing as the object falls
meaning it is not constant, it ACCELERATES

Answer 8

but wouldnt the object will have speed once it lands ?

Answer 9

on the ground velocity = 0
before the moment it hits the ground, it depends on the height at which it was coming

Answer 10

the height is 65cm

Answer 11

0.65 meter is the height?

Answer 12

@Orwell84 ??

yh @nincompoop

Answer 13

can u pls explain this using one of your example @nincompoop

Answer 14

yh but it doesnt relate it to me so pls keep this matter out of my post,

Answer 15

converting 2.818 RPM to radians per sec and substitute back,,,,,u get
g=9.79 ...

Answer 16

I am going to assume that this involves no angle, but only a free fall and the object was at rest so the initial velocity is zero.
use the formula
s(t) = -4.5t^2 + 0 + .65

Answer 17

a good example:
a ball is thrown upward with an initial velocity of 15 meters/second from an initial height of 500 meters.
a) find the position function giving height as s as a function of time t
b) when does the ball hit the ground?
c) how fast the ball just the moment it hits the ground?

Answer 18

You have to solve your equations this way:
- solve for t by choosing z=0 (the body touches the ground)
- use that value of t to find out the values of the components of the velocity

Answer 19

@nincompoop

Answer 20

s(t) = -4.5t^2 + 0 + .65
???

Answer 21

You can also use conservation of mechanical energy. It will directly give velocity with respect to initial height.

Answer 22

but I dnt have any values from where I can use the conservation of mechanical energy

Answer 23

@rane that is your position function
-4.5t^2 is the acceleration due to gravity
+ 0 is the initial velocity
.65 is the initial position

if you want to solve for the velocity (what you refer to as speed) you first need to know when the object hits the ground by setting your distance into 0 since the distance at the ground is zero.
s(t) = -4.5t^2 + 0 + .65 = 0
solve for t using quadratic formula
t ≅ 0.38 sec
apply this time into the derivative of the position function to get the velocity
s(t) = -9.8t
s(0.38) = -9.8(0.38) ≅ -3.72 meters/sec

Answer 24

@UnkleRhaukus @hartnn