[Student21]

Hi Every1

Got question on vectors which i cant handle, can some please show me how to go through this, thankyou!

A body has initial velocity u ms-1 and accelerates uniformly at a ms-2 for t
seconds, reaching a velocity of v ms-1.
The relationship between these measures is:
v = u + at.
Its displacement, s metres, over this period is given by:
s = ut + 0.5at^2

1. A body is initially at rest and accelerates for 8 secs at

5
-1 ms-2
2
a) what is its final velocity and b) what is its displacement

I've worked out the final velocity to be

40
-8
16

How do you work out displacement??

[Spungo]

(Original post by Student21)
Hi Every1

Got question on vectors which i cant handle, can some please show me how to go through this, thankyou!

A body has initial velocity u ms-1 and accelerates uniformly at a ms-2 for t
seconds, reaching a velocity of v ms-1.
The relationship between these measures is:
v = u + at.
Its displacement, s metres, over this period is given by:
s = ut + 0.5at^2

1. A body is initially at rest and accelerates for 8 secs at

5
-1 ms-2
2
a) what is its final velocity and b) what is its displacement

I've worked out the final velocity to be

40
-8
16

How do you work out displacement??

What is the -8 and 16 for?
You've also answered your question in your own post. Read it again.

[raheem94]

(Original post by Student21)
Hi Every1

Got question on vectors which i cant handle, can some please show me how to go through this, thankyou!

A body has initial velocity u ms-1 and accelerates uniformly at a ms-2 for t
seconds, reaching a velocity of v ms-1.
The relationship between these measures is:
v = u + at.
Its displacement, s metres, over this period is given by:
s = ut + 0.5at^2

1. A body is initially at rest and accelerates for 8 secs at

5
-1 ms-2
2
a) what is its final velocity and b) what is its displacement

I've worked out the final velocity to be

40
-8
16

How do you work out displacement??

The final velocity is , why have you written -8 and 16 after it?

For displacement use the formula, , we know the acceleration, time and initial velocity so displacement can be worked out.

[Student21]

(Original post by raheem94)
The final velocity is , why have you written -8 and 16 after it?

For displacement use the formula, , we know the acceleration, time and initial velocity so displacement can be worked out.

The question had a column vector so my answer was also a column vector. I just did not know how to put the big brackets into a html page. I've checked my answer and it is right and includes the -8 and 16. What i cannot work out is the displacement in column vector form.

Edit ive added a pic of the question sheet

[raheem94]

(Original post by Student21)
The question had a column vector so my answer was also a column vector. I just did not know how to put the big brackets into a html page. I've checked my answer and it is right and includes the -8 and 16. What i cannot work out is the displacement in column vector form.

Edit ive added a pic of the question sheet

Try to work out the displacement in the same way, first use, a=-5, then a=-1, then a=2.

For the first row, input, a=5, t=8, in

Find the displacement, use a similar method to find the other 2 rows.

[raheem94]

(Original post by Student21)
The question had a column vector so my answer was also a column vector. I just did not know how to put the big brackets into a html page. I've checked my answer and it is right and includes the -8 and 16. What i cannot work out is the displacement in column vector form.

Edit ive added a pic of the question sheet

Is the answer to this displacement part,

[Student21]

(Original post by raheem94)
Try to work out the displacement in the same way, first use, a=-5, then a=-1, then a=2.

For the first row, input, a=5, t=8, in

Find the displacement, use a similar method to find the other 2 rows.

I just found out the answers on the answer sheet are not even correct. I was getting the right answers all along. Thanks for the help anyways, it was much appreciated.

Yes the answer you got is the correct one.