Question

I have a few GRADE 11 PHYSICS questions. It is about Motion and mechanics, such as projectiles and distances...vectors. Please let me know when you have read this so i can ask you the questions in the chat.

Answer 1

hiii

Answer 2

ok
So my questions are...

Answer 3

yes

Answer 4

in a projectile motion thing...

Answer 5

there’s values that i have to search for, such as range (dx, which is horizontal distance) or time (which is mutual between y and x values.

Answer 6

if i were presented a context in which i had to find the dy
and that there was a cannon shooting upwards and then the cannon goes up and falls back down while moving forward.

Answer 7

the cannon is on an elevated surface

Answer 8

is dy the distance from the ground to the cannon or the ground to the max height?

Answer 9

i can give you the exact question if you would like.

Answer 10

A cannonball is shot out of a cannon with a horizontal velocity A
component of 40 m/s and a vertical velocity component of 20 m/s
[up]. If the cannon is sitting at the top of a cliff 100 m high, how
far will the cannonball travel?

Answer 11

so you have to solve for dx
could you show me how?

Answer 12

dy refers to change in y or change in height

whether it is max height or some other value will depend on the specific question..

Answer 13

could you solve this for me?

A cannonball is shot out of a cannon with a horizontal velocity A
component of 40 m/s and a vertical velocity component of 20 m/s
[up]. If the cannon is sitting at the top of a cliff 100 m high, how
far will the cannonball travel?

you have to find dx i guess

Answer 14

okk

Answer 15

x = 40 t . so we need to find t now

Answer 16

x velocity is 40 m/s

Answer 17

yes

Answer 18

using vertical motion , we ll find t

Answer 19

time of goin up plus time of coming down to same height plus time of goin down to ground

Answer 20

i don’t understand

Answer 21

x = 40 t . so we need to find t now. is this clear?

Answer 22

why t?

Answer 23

we assume it will take time t

Answer 24

do you mean 40 times t?

Answer 25

yes

Answer 26

ohhh cause distance = speed x time ?

Answer 27

yess

Answer 28

but that’s not what they mean
they mean what is the horizontal distance

Answer 29

pardon me?

Answer 30

I have the explanation and answer but it says that you have to take firstly the x values and then the y values and then you take them into some weird quadratic equation like
\[d = (1/2)at^2 + vt\]

Answer 31

and then like you have to solve for t with the givens

Answer 32

@fahminator that 'weird quadratic eq' is one of Newton's three kinematic eqs :
s = ut + 1/2 at^2
now, considering only the horizontal motion, a = 0 since the acceleration on the cannon ball is that due to gravity which is always vertically downwards.
so the above eq now becomes,
x = ut..........[taking s = x, coz we're finding the horizontal disp]
x = 40t.
this is how @telltoamit got this eq.
so to find x, first we need to find t.