a particle has posotin vector 2i + j initially and is moving with speed 10 ms^-1 in the direction 3i - 4j. The answer is 20i - 23j .
Please explain how does it get. Thank you.
2007-05-26 02:56:27 · 2 answers · asked by ela kolla 2 in Science & Mathematics ➔ Mathematics
A unit vector in the direction 3i - 4 j is (3i -4 j)/5
{simply divide by its length}.
In 3 seconds, the body moved 30m.
multiply magnitude by direction to get 18i-24j.
Suppose he is finally at point C, then OC=
OB + BC = 2i + j + 18i - 24j = 20i - 23j. qed.
2007-05-26 03:13:40 · answer #1 · answered by Anonymous · 1⤊ 0⤋
the unit vector in the given direction is (3i-4j)/5
so its velocity vector is
v(t) = (3i-4j)/5 *10 and the position vector is the integral
x(t)=(3i-4j)*2 t +C where C is a constant vector.At t=0
x(0)=C=2i+j
so x(t) = (6i-8j)t+2i+j and at t=3
x(3) = 20i-23j
2007-05-26 03:16:47 · answer #2 · answered by santmann2002 7 · 1⤊ 0⤋