College Physics 1 Homework Chapter 3.5

Question

#9.) The x-component of a velocity vector that has an angle of 31 ∘ to the +x-axis has a magnitude of 5.8 m/s .

A.) What is the magnitude of the velocity? Express your answer using two significant figures.

B.) What is the magnitude of the y-component of the velocity? Express your answer using two significant figures.

Answer 1

(A)

 

v_x = v cosθ ⇒ v = v_x/cosθ = 5.8/cos31° m/s = 6.77 m/s

 

(B)

 

v_y = √(v² - v_x²) = √[(6.77)² - (5.8)²] m/s = 3.49 m/s

 

You can round off to 2 significant digits if you wish.