Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Using three vectors a, b, and c from the sample problem in the photo, obtain the

ID: 1397053 • Letter: U

Question

Using three vectors a, b, and c from the sample problem in the photo, obtain the following:

a. 3a - 2.5c

b.absolute value (2b + 5a)

c. angle between 3.2c - 1.7b and the y axis

Adding vectors, unit-vector components Figure 3-17a shows the following three vectors: a (4.2-(1.5 m).. F-(-1.6 m), (2.9 m c' = (-3.7m).. We can add the three vectors by components, axis by axis, and then combine the components to write the vector sum r. and culations For the x axis, we add the x componcnts of a, b, and to get the x component of the vector sum r: What is their vector sum r which is also shown? = 4.2 m . 1.6 m () 2.6 m. To add these vectors, find their net x component Similarly. for the y axis, and their nel y component. -1.5 m 2.9 m-3.7 m =-2.3 m. 3-1 We then combine thesc componcnts of to write the vector in unit vector notation: -1 -2 = (2.6 m)1-(2.3 m), (Answer) Then arrange lhe net components head lo tail. where (2.6 im)i is the vector component of 7 along the x axis and (2.3 m)j is that along the y axis. Figure 3-17b shows one way to arrange these vector components to form . (Can you sketch the other way?) s 2.6i We can also answer the question by eiving the magnitude and an angle for F. From Eq.3-6, the magnitude is -1 r- V(2.6 m) 2.3 m) 3.5m (Answer) r=V'(2.6 m)? +(-2.3 m),3.5m -2 (Answer) and the anglc (measured from the + direction) is = tan-1 -2.3 m 1 ]--41 -41(Answer) (b)- This is the result af the addition. is the vector sum of the other three vectors. Figure 3-17 Vector where the minus sign mcans clockwise.

Explanation / Answer

here,

a = 4.2 i - 1.5 j

b = -1.6 i + 2.9 j

c = -3.7 j

(a)

let A = (3a - 2.5 c)

A = 3(4.2 i - 1.5 j) - 2.5(-3.7 j)

A = (12.6 i + 7.75 j )m

(b)

let B = (2b + 5a)

B = 2(-1.6 i + 2.9 j) + 5(4.2 i - 1.5 j)

B = 17.8 i - 1.7 j

|B| = sqrt(17.8^2 + 1.7^2)

|B| = 17.89 m

absolute(2b +5a) = 17.89 m

(c)

C = 3.2c - 11.7b

C = 3.2(-3.7 j) - 1.7(-1.6 i + 2.9 j)

C = 2.72 i - 16.77 j

angle with y - axis , theta = 180 + arctan(2.72/16.77)

theta = 189.21 degree

the angle between (3.2c - 1.7b) and positive y axis is 189.21 degree