True or False Questions?

Question

The 'net force' in the statements below is the sum of ALL forces acting on the body. True or False
1. During the collision of a locomotive with a car, the car exerts an equal size force on the locomotive as the locomotive exerts on the car.
2. An object's velocity will change if a net force acts on the object.
3. If two objects are under the influence of equal forces, they have the same acceleration.
4. The net force which acts on an object which maintains a constant velocity is zero.
5. If a net force acts on an object, the object's speed will change.
6. In order not to slow down, a truck moving at a constant velocity needs a small net force applied.

Explanations would be good too :) Thanks

Answer 1

1. True.
2. True.
3. True, at least for equal NET forces. Forces of equal power applied in different directions may add up to different net forces, so they would not be included. All forces must be of the same power and in the same direction.
4. True.
5. False. The object could change direction while its speed remains the same.
6. False. It needs some POWER applied, enough to keep it from slowing down. However this is just to counteract the friction force and there is no net force.

Answer 2

1. True. This is an example of Newton's 3rd Law.
2. True. This is what Newton's 2nd Law says.
3. False. Only true if the two objects have the same mass. This is predicted by Newton's 2nd Law, which says a = F/m.
4. True. If velocity is constant, acceleration is zero, by definition. This means F/m = 0 (by Newton's 2nd Law), which means F = 0.
5. False. By Newton's 2nd Law, the object's VELOCITY will change; but this does not necessarily mean its speed changes. That's because velocity is a vector. So a change in velocity means: a change in speed OR a change in direction OR both. A net force may cause a change in direction without causing a change in speed.
6. Actually False, but because of the way it is worded, I expect the teacher's intention was that this should be "True". By Newton's 2nd Law, if the truck is moving at constant velocity (which also implies it is not slowing down), then there is zero net force on it; so the statement is false. However, my guess is that the point the teacher was making was this: that if the truck "coasts" down the street, friction will exert a force backwards and slow the truck down; therefore it's necessary to exert a small forward force (by means of the engine) to keep this from happening. I would say "False," and if your teacher marks it incorrect, contest it!

Answer 3

1. True. This is Newton's third law.
2. True. This is Newton's second law.
3. False, unless their masses are equal. F = ma, so if F is the same, a will be different unless m is the same.
4. True, same as #2.
5. False. The velocity can change while the speed is constant if the object is moving in a circle. Velocity = speed and direction.
6. False. If the truck is moving at a constant velocity, there is no net force. (How the truck gets to move at a constant velocity presumably involves a variety of forces, including friction between the tires and the ground, air resistance, internal friction, gravity if the truck is on a hill, and so forth; that's not what the question asks, though). Personally, I don't like this question; there are too many ways to arrive at a wrong answer for it to be useful on a test, imho.

Answer 4

1. True, this is newton's 3rd law.
2. True, but be carefull that a net force alwase would not make a change in SPEED, for example in a circular motion the net force exerted on an object can just change the direction of motion of the object, not its speed.
3. False, newton 2nd law: F=ma, so equal forces do not make same accelaration on to different objects.
4. True, F=ma, a=0 => F=0
5. False, see answer of question 2
6. WRONG QUESTION!!! Being small and big is something relative, 1 is small with respect to 1000000000, but is big with respect to 0.000000000000000001 so you could not say small force or big force without according to sth else.

Answer 5

You're bored proper now? False It's raining wherein ever you're proper now? False You're by myself proper now? False You plan to stick residence this night? False You don't forget your self intriguing? True You uncover a Y!A consumer intriguing? True You could don't forget assembly a Y!A consumer in individual? True You have cheated to your associate earlier than? FALSE You had been cheated through your associate earlier than? TRUE You preferred this survey? real You will celebrity this question? real

Answer 6

1 - T
2 - F
3 - T
4 - T
5 - F
6 - T
Hmm... I am not sure !!! Better check it from ur friends !

Answer 7

am I doing your homework?