# Vector A is described as having magnitude 5 and angle -20°.

label Physics
account_circle Unassigned
schedule 1 Day
account_balance_wallet \$5

8. Vector A is described as having magnitude 5 and angle -20°. Which is an equivaent statement of magnitude and angle of vector A? (Note: All angles are measured counterclockwise from the x-axis.)

10.

 A boy throws a rock with an initial velocity of 2.5 m/s at 30.0° above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory?
May 18th, 2015

8. Equivalent statement will be, magnitude = 5 and angle = 360-20 = 340 degrees

= 5* cos(20 degrees) i - 5*sin (-20 degrees)

=4.698 i - 1.71 j

10) Initial Vy = 2.5 sin(30 degrees) = 2.5/2 = 1.25

At highest point, Vy = 0

Considering a = g = -9.8 m/s^2

t = -1.25/9.8

=0.127 s

May 18th, 2015

number 8 options

magnitude -5; angle 160°

magnitude -5; angle 20°

magnitude 5; angle 160°

magnitude 5; angle 20°

magnitude 5; angle 70°

number 10 options..

0.194 s

0.215 s

0.303 s

0.110 s

May 18th, 2015

8) 160 (option 2)

10) 0.110 seconds (option 4)

May 18th, 2015

8. negative 5 or positive?

May 18th, 2015

magnitude is never negative hence, positive 5

May 18th, 2015

...
May 18th, 2015
...
May 18th, 2015
Nov 18th, 2017
check_circle