A certain force exerted for $1.2 \mathrm{s}$ raises the speed of an object from $1.8 \mathrm{m}/\mathrm{s}$ to $4.2 \mathrm{m}/\mathrm{s}$. Later, the same force is applied for $2 \mathrm{s}$. How much does the velocity change in $2 \mathrm{s}$?

The speed-time graph of a car of $1000 \mathrm{kg}$ mass is given. On the basis of this, answer the following question.

What is the maximum force acting on the car?

The speed-time graph of a car of $1000 \mathrm{kg}$ mass is given. On the basis of this, answer the following question.

What is the retarding force acting on the car?

The speed-time graph of a car of $1000 \mathrm{kg}$ mass is given. On the basis of this, answer the following question.

For how long is no force is acting on the car?

The speed-time graph of a car of $1000 \mathrm{kg}$ mass is given. On the basis of this, answer the following question.

What is the velocity of the car from $4 \mathrm{s}$ to $8 \mathrm{s}$?