{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Physx141MPch3sol

Physx141MPch3sol - 3.7 Visualize The figure shows the...

This preview shows pages 1–3. Sign up to view the full content.

3.7. Visualize: The figure shows the components v x and v y , and the angle θ . Solve: We have, sin40 , y v v = − ° or 10 m/s sin40 , v = − ° or 15.56 m/s. v = Thus the x -component is cos40 (15.56 m/s ) cos40 11.9 m/s. x v v = ° = ° = Assess: Note that we had to insert the minus sign manually with y v since the vector is in the fourth quadrant. 3.8. Visualize: Solve: Vector E r points to the left and up, so the components x E and y E are negative and positive, respectively, according to the Tactics Box 3.1. (a) cos x E E θ = − and sin . y E E θ = (b) sin x E E φ = − and cos . y E E φ = Assess: Note that the role of sine and cosine are reversed because we are using a different angle. θ and φ are complementary angles. 3.10. Visualize: We will follow the rules given in the Tactics Box 3.1. Solve: (a) (2 km)sin30 1 km x r = − ° = − (2 km)cos30 1.73 km y r = ° = (b) (5 cm/s)sin90 5 cm/s x v = − ° = − (5 cm/s)cos90 0 cm/s y v = ° = (c) 2 2 (10 m/s )sin40 6.43 m/s x a = − ° = − 2 2 (10 m/s )cos40 7.66 m/s y a = − ° = −

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
(d) (50 N)sin36.9 30.0 N x F = ° = (50 N)cos36.9 40.0 N y F = ° = Assess: The components have the same units as the vectors. Note the minus signs we have manually inserted according to the Tactics Box 3.1. 3.12. Visualize: Solve: The magnitude of the vector is 2 2 2 2 ( ) ( ) (125 V/m) ( 250 V/m) 280 V/m. x y E E E = + = + − = In the expression for , E v the and + means that ˆ j ˆ i E r is in quadrant IV. The angle θ is below the positive x -axis. We have: | | 1 1 1 250 V/m tan tan tan 2 63.4 125 V/m y x E E θ = = = = ° Assess: Since | | | | y x E E > , the angle θ
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 5

Physx141MPch3sol - 3.7 Visualize The figure shows the...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online