help on science?

Question

homework help?
i dont understand this help please! and please dont just guess

a table top is not at level. you know this because a toy car rolls off the table when you place it at rest on the table top. using a stop watch and a meter stick , you make some measurements and find that the car rolls at constant speed. which of the following statements is true?

a things that roll down slopes are really accelerating, even if they are moving at constant speed.
b when the car is at a constant speed , the forces on the car are in balance, adding togheter to equal zero.
c no forces are acting on the car, because it is moving at constant speed.
d the inertia of the car is not constant because it is changing position

i have to explain why or why not

Answer 1

a) Things that are moving at a constant speed cannot be accelerating. Acceleration is the rate of change of Velocity with respect to time. Thus, if a body is accelerating, it is increasing its velocity.

b) If all the forces acting on the car were in balance, it would be at rest (not moving).

c) There is always the force of gravity acting on the car. whether the car is at rest or moving.

Inertia is the property that tends to keep an moving object moving and a object at rest to stay at rest.

Answer 2

the car couldn't roll at a constant speed because gravity would make it accelerate unless their is so much friction that the cars speed cannot increase further

Answer 3

b The forces are equal. The acceleration do to gravity is equal to the forces slowing the car namely friction(wheels on tabletop and wheels to axles) and wind resistance (though minimal at that speed).

Answer 4

ok A makes no sense. if you are going in constant speed, you cannot accelerate. if you are accelerating, you will not go in a constant speed.

C. is wrong.

D. is wrong

B. so only b makes sence.