10 Questions

Priority Level: High (ECE)

Questions and Answers

- 1.An object which weighs 10 N is dropped from rest from a height of 4 meters above the ground. When it has free-fallen 1 meter its total mechanical energy with respect to the ground is ____.
- A.
2.5 J

- B.
10 J

- C.
30 J

- D.
40 J

- 2.
- A.
A vector is a large quantity and a scalar is a small quantity

- B.
A scalar quantity has a magnitude and a vector quantity does not

- C.
A vector quantity is described with a direction and a scalar is not

- D.
A scalar quantity depends only upon the initial and final values of the quantity; this is not the case for vector quantities

- 3.If car A passes car B, then car A must be ____.
- A.
Accelerating

- B.
Accelerating at a greater rate than car B

- C.
Moving faster than car B and accelerating more than car B

- D.
Moving faster than car B, but not necessarily accelerating

- 4.A truck driving along a highway road has a large quantity of momentum. If it moves at the same speed but has twice as much mass, its momentum is ________________.
- A.
Zero

- B.
Quadrupled

- C.
Doubled

- D.
Unchanged

- 5.Two objects, A and B, have the same size and shape. Object A is twice as massive as B. The objects are simultaneously dropped from a high window on a tall building. (Neglect the effect air resistance.) The objects will reach the ground at the same time but object A will have a greater ___.
- A.
Speed

- B.
Acceleration

- C.
Momentum

- D.
None of the above quantities will be greater

- 6.
- A.
2.32 s

- B.
3.6 s

- C.
0.45 s

- D.
0.94 s

- 7.A 945-kg car traveling rightward at 22.6 m/s slams on the brakes and skids to a stop (with locked wheels). If the coefficient of friction between tires and road is 0.972, determine the distance required to stop.
- A.
13.4 m

- B.
26.8 m

- C.
8.6 m

- D.
17.2 m

- 8.An engineer is designing the runway for an airport. Of the planes that will use the airport, the lowest acceleration rate is likely to be 3 m/s
^{2}. The takeoff speed for this plane will be 65 m/s. Assuming this minimum acceleration, what is the minimum allowed length for the runway?- A.
704 m

- B.
436.5 m

- C.
032 m

- D.
1607 m

- 9.A baseball is popped straight up into the air and has a hang-time of 6.25 s. Determine the height to which the ball rises before it reaches its peak.
- A.
47.9 m

- B.
123 m

- C.
78.2 m

- D.
93.7 m

- 10.In a physics experiment, two equal-mass carts roll towards each other on a level, low-friction track. One cart rolls rightward at 2 m/s and the other cart rolls leftward at 1 m/s. After the carts collide, they couple (attach together) and roll together with a speed of _____________. Ignore resistive forces.
- A.
0.5 m/s

- B.
0.33 m/s

- C.
0.67 m/s

- D.
1.0 m/s