Physics 42?

Question

Suppose E= 2A + 3B where vector A has components A_x = 5, A_y = 2 and vector B has components B_x = -3, B_y = -5.

What is the x-components of vector E?

What is the y-components of vector E?

What is the magnitude of vector E?

What is the direction of vector E (as theta = __ degrees below + x-axes)?

Answer 1

A = (5, 2)

B = (- 3, - 5)

E = 2A + 3B

= 2(5, 2) + 3(- 3, - 5)

= (10, 4) + (- 9, - 15)

= (1, - 11).

x component is 1.

y component is - 11.

Magnitude of E is sqrt(1^2 + 11^2)

= sqrt(122)

= 11.0 to 3sf.

If t is angle below x axis:

tan(t) = 11

t = 84.8 deg.