Question

Help please...

Answer 1

http://screencast.com/t/qsnov6Jg

Answer 2

2) B part only

Answer 3

@sasogeek @ParthKohli @Ishaan94 @inkyvoyd @Ishaan94 @Callisto

Answer 4

i got the equation W.D= Force * distance and the answer was correct, but how do we find this using F=ma

Answer 5

So did you find the force in 2B?

Answer 6

mv^2/2 = -W.D = Force * distance

Answer 7

v = v at point B

Answer 8

yep 6667N

Answer 9

how to find the acceleration in this @ArchiePhysics

Answer 10

average acceleration = average force / mass

Answer 11

the mass is given 85 kg

Answer 12

Oh but the acceleration?

Answer 13

Ok let's make it clear. What do you need to find?
Is that acceleration instanteous acceleration through path form B to P?

Answer 14

i need to find the Force using the equation F=ma...I need to know the acceleration for that...the method to find the acceleraton

Answer 15

You are given initial velocity u at point B, distance and assuming that acceleration is constant you can find it, using kinematics equation.
s = ut+at^2/2

Answer 16

u = at

Answer 17

sorry u = -at

Answer 18

where is time? then

Answer 19

t = u/-a

Answer 20

then acceleration we dint find right...

Answer 21

cn u solve this and show

Answer 22

I don't have any paper right now, if you will wait for 5 minutes yes, I will show you.

Answer 23

okay

Answer 24

Using the two equations I gave you, you can derive this formula
a = - u^2/(2s)

Answer 25

can we do this without the use of kinematics...

Answer 26

If not kinematics then only energy - work approach, but you declined it at the beginning.

Answer 27

oh alright...but i am doin grade 10, and in the marking scheme it s provided...F=ma, so i thought f finding an easy one.

Answer 28

Ok. I see.