Question

Two particles A and B are simultaneously projected from the same point on a horizontal plane. The initial velocity of A is 15m/s at 25 degree to the horizontal and the initial velocity of B is 15m/s at 65 degree to the horizontal.
a)Construct a diagram showing paths of both particles until they strike the horizontal plane.
b) from your diagram estimate the time each particle is in the air
c) calculate these times correct to 3 s.f

Answer 1

Particle A
x horizontal velocity of magnitude=vcosѲ=15cos25=13.6
y vertical velocity of magnitude=vsinѲ=15sin25=6.35
Particle B
x horizontal velocity of magnitude=vcosѲ=15cos65=6.35
y vertical velocity of magnitude=vsinѲ=15sin65=13.6

Answer 2

it is b i think

Answer 3

thats not a multiple question @mistyrforrest

Answer 4

multiple choice**

Answer 5

: )

Answer 6

can i ask you a question both will travel the same ditance.
when applying pythageorn theorm both particles will exert the same velocity and eventually the same distance.

Answer 7

your velocity components look correct to me
i'm not sure if they will travel the same distance, maybe not
i'm not sure what your last statement means, but don't worry about that

Answer 8

what you have to do is pick a particle, let's start with A
then focus your mind on the vertical motion
and with v = u-gt applied to the vertical motion you can work out the time of flight

Answer 9

v=6.35-10t

Answer 10

yes, and we know v as well

Answer 11

you remember, it will have the same speed coming down at a particular height, as it had on the way up, just going in the opposite direction

Answer 12

so v = -6.35

Answer 13

when it hits the ground again

Answer 14

yes you are right :),

Answer 15

-6.35-6.35/-10=t t=1.27s

Answer 16

yes, that looks right

Answer 17

and now because you know the horizontal speed of particle A you can figure out how far it went horizontally in that time

Answer 18

s=ut
s=13.6*1.27=17.3

Answer 19

you got it : )

Answer 20

same thing to particle B

Answer 21

now just go through the same procedure for particle B

I think you were right when you suspected they both go the same distance, i think you will find the same distance for particle B, i wasn't sure at first

Answer 22

yes

Answer 23

-13.6-13.6/-10=2.72 s
s=6.32*2.72=17.12
thank you so much :D

Answer 24

well done - problem solved

Answer 25

although we skipped the estimating part
and remember the question asked for 3 significant figures in your answers to part c
: )