Question 7 (1 point)
Unbalanced forces
a
maintain the constant motion of an object.
b
can change an object's speed but not direction.
c
cause the motion of an object to change.
d
make an object move opposite the applied force.
c
Question 8 (1 point)
Every few years, sailboats of different countries compete in a race for a trophy called the America's Cup. The boats sail over the same distance. What, besides the distance, is needed to find out the speed of each boat in the race?
a
the time it takes each boat to finish the race
b
the size of each boat in the race
c
the skill of the crew of each boat in the race
d
the speed of the wind during the race
a
The correct answer is c) cause the motion of an object to change.
To understand why unbalanced forces cause the motion of an object to change, we need to look at Newton's first law of motion, also known as the law of inertia. This law states that an object at rest will remain at rest, and an object in motion will continue moving at a constant speed in a straight line, unless acted upon by an external force.
When multiple forces are applied to an object and they are not balanced, meaning that the net force is not equal to zero, the object will experience an acceleration in the direction of the net force. This acceleration will cause the object's motion to change.
For example, if a book is resting on a table and you push it with an unbalanced force, the book will start to move in the direction of the applied force. If the force is applied in the opposite direction of the book's initial motion, it will slow down and eventually come to a stop before changing its direction and moving in the opposite direction.
Therefore, unbalanced forces cause the motion of an object to change by either speeding it up, slowing it down, or changing its direction.