Post by: man0005 on February 03, 2011, 10:37:18 pm
Post by: m@tty on February 03, 2011, 10:50:44 pm
Where are B and A?
Question 18.
Velocity can be deduced by the gradient of a distance-time graph (think about it, it's logical - if you travel further in the same time, shown by a steeper slope, you must be going faster).
This is confusing.. Um, I'll think about it =\
Question 5.
Question 6.
Y being independent of x means that the value of x has no effect on the value of y - thus (ii) as y does not change when x does.
Post by: man0005 on February 03, 2011, 10:53:12 pm
here it is
Post by: man0005 on February 03, 2011, 10:56:44 pm
here it is
Post by: m@tty on February 03, 2011, 10:59:01 pm
With vector addition you place each vector head-to-tail.
Subtracting a vector is the same as adding a vector in the opposite direction.
A scale factor changes the magnitude, or length of the vector.
So in this case you flip A and stretch it to twice it's original size, then place the tail onto the tip of vector B. The resulting vector points down and to the left.
You visualise all that, it's easier than you may think.
Post by: moekamo on February 03, 2011, 10:59:18 pm
9. B-2A = B+ (-2A) so you reverse A, make its length double and add to B, should give you option B
Post by: moekamo on February 03, 2011, 11:03:42 pm
then if v=0, displacement is constant,
but when v drops suddenly to a negative constant value, displacement will decrease linearly, as in D, but not B so answer must be D
Post by: man0005 on February 03, 2011, 11:07:10 pm
really appreciate it :)
Post by: taiga on February 03, 2011, 11:15:19 pm
Post by: man0005 on February 16, 2011, 06:01:26 pm