Question

1.) Name a vector quantity and its magnitude.

2.) What is a scalar quantity? Give two examples.

For Questions 3, 4, and 5, use the following values:

A = 5.0 N at 135.0 degrees B = 6.0 N at 270.0 degrees

If you get the same answer for Questions 3 and 4, it is wrong!

3.) Using the component method, add vectors A and B (ex: R = A + B).

4.) Using the component method, add vectors A and -B (ex: R = A - B).

5.) Using the Tail-to-head method, add vectors A and B (R = A + B), on the back of this sheet. Let 2.0 cm = 1.0 N.

Answer 1

(1) Vector quantity -

A quantity which has both magnitude as well as direction is called a vector quantity. Example - (i) Velocity - it has both magnitude and direction.

(ii) Electric field - it has both magnitude and direction.

(2) Scalar quantity -

A quantity which has only magnitude is called the scalar quantity. Example - (i) Speed - it has only magnitude.

(ii) Temperature- it has only magnitude.

(3) Write the vectors in unit vector notations -

A = (5.0*cos 135)i + (5.0*sin135)j = ( -3.53i + 3.53j) N

B = (6.0*cos 270)i + (6.0*sin270)j = (0 - j) N

So, R = A + B = ( -3.53i + 3.53j) N + (0 - j) N = (-3.53i + 2.53j)N

(4) R = A - B = ( -3.53i + 3.53j) N - (0 - j) N = (-3.53i + 4.53j)N