1Which statement correctly applies to a car that changes its velocity over a period of time?
aThe combination of all forces acting on it is zero.
bNo net force is acting on it.
cA nonzero net force is acting on it.
dForces are acting on it.

2A group of students conducted several trials of an experiment to study forces and the acceleration they produce on a given object. The students decided to present the resulting data using a graph rather than a table. Which statement describes an advantage of presenting the data using a graph
a
Graphs visually show the relationship between the variables under investigation.
b
Tables cannot explicitly show the data from the investigation.
c
Graphs are more appealing than tables.
d
Tables with many rows of data are not very useful.

1) Velocity is same as speed just that it has direction. Now Newton's first law of motion which is called law of inertia states that an object will continue in its present state of rest rest or remain in constant motion unless an external force acts on it.

This means that for a cars speed to change, according to this law, it means external forces have acted on it.

Thus, option D is correct.

D; Forces are acting on it.

2) We want to show the relationship between force and acceleration using either table or graph.

Now, a table will just use rows and columns to show us the value of a force per given acceleration. It doesn't show us a trend in terms of line or curve like the way graph will show.

This means that graphs give a better visual representation of the relationship between two variables than tables will do.

Thus, option A is correct.