The resistance of a wire, R ohms , is directly proportional to its length, I m, and inversely
proportional to the square of its radius, r m.
(a) Express R in terms of l, r and a constant k.
(b) Make r the subject of the formula in (a).
(c) (ii) Given that a wire with a length of 2 m and
a radius of 0.5 cm has a resistance of 40 ohms,
use your answer in (a) to find the value of k.
(ii) Hence, use your answer in (b) to find the
radius of a wire with a length of 4 m and a
resistance of 60 ohms.

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

step-by-step explanation:

use pothagarean therom

a^2+b^2=c^2 so first ac

acm is a right triangle because c= 90°

and am (the hypotenuse or c) =16+9 =25

but there is not enough info we need another angle or side length

in 1995, potato plants were taken into space aboard the space shuttle columbia.

step-by-step explanation: