Engineering Mechanics Practice Test 1

1. What is the angle made by the vector shown in the figure, with the z-axis?

45°

90°

30°

60°

2. If a car is moving forward, what is the direction of the moment of the moment caused by the rotation of the tires?

It is heading outwards, i.e. the direction is towards outside of the car

It is heading forward, i.e. the direction is towards the forward direction of the motion of the car

It is heading backward, i.e. the direction is towards the back side of the motion of the car

It is heading inwards, i.e. the direction is towards inside of the car

3. What is the value of {(AxB).(C.D)x(AxB).(C.D)}? For the four vectors A, B, C and D, with A, B, C and D all lying in the same plane?

i + j + k

-1(i + j + k)

√3(i + j + k)

4. What is the dot product of the components of the force vector shown in the figure, i.e. the dot product of the z-axis component and the y-axis component of the force?

200sin45°

200cos60°

200cos30°

5. Which of the following statement is true?

A vector is any positive or negative physical quantity that can be completely specified by its magnitude

A scalar is any physical quantity that requires both a magnitude and a direction for its complete description

A scalar is any physical quantity that can be completely specified by its direction

A scalar is any physical quantity that can be completely specified by its magnitude

6. ∑Fx=0, ∑Fy=0 and ∑Fz=0 are vector equations.

True

False

7. The coordinate of the Force vector AB is A (2, 0, 2) and B (-2, 3.46, 3). What are its directions?

-0.742i - 0.643j + 0.186k

0.742i - 0.643j - 0.186k

-0.742i + 0.643j - 0.186k

-0.742i + 0.643j + 0.186k

8. Find the tension in the cable AC.

23.6N

55N

89N

-29N

9. Determine the magnitude of the projection of the vector force F = 100N, onto u axis, from the figure given below.

60N

96.6N

100N

70.7N

10. What is the magnitude of the resultant vector’s unit vector? (Resultant vector of the two vectors shown in the figure below)

55N

225N

110N