$A$ force can be completely described by

Name the physical quantity whose $SI$ unit is "newton".

State whether the following statement is true or false:
Force may or may not produce any motion in a body.

Name the force which is responsible for change in position or state of an object.

$A$ $8000 \,kg$ engine pulls a train of $5$ wagons,each of $2000 \,kg$,along a horizontal track. If the engine exerts a force of $40000 \,N$ and the track offers a friction force of $5000 \,N$,then calculate the net accelerating force (in $N$).

Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?