Physics help please!! 10 points?

[Girl]

multiple choice. i would really appreciate it!!

1. The circuit of a motor racing track is 3 km in length. In a race, a car goes 25 times round the circuit in 30 minutes.
What is the average speed of the car?

A. 75 km / hour
B. 90 km / hour
C. 150 km / hour
D. 750 km / tour

2. What is the meaning of the weight of an object?

A. the density of the material from which it is made
B. the force exerted on it by gravity
C. the mass of the matter it contains
D. the pressure it exerts on the floor

3. Four students try to explain what is meant by acceleration.
Which student makes a correct statement?

A. It is related to the changing speed of an object.
B. It is the distance an object travels in one second.
C. It is the force acting on an object divided by the distance it travels in one second.
D. It is the force acting on an object when it is near to the Earth.

4. A child is standing on the platform of a station, watching the trains.

A train travelling at 30 m / s takes 3 s to pass the child.
What is the length of the train?
A. 10 m
B. 30 m
C. 90 m
D.135 m

5. A person measures the length, width, height and mass of a rectangular metal block.

Which of these measurements are needed in order to calculate the density of the metal?
A. mass only
B. height and mass only
C. length, width and height only
D. length, width, height and mass