Forces and motion

An unbalanced force can make all of these things happen except...

• a moving object changes direction
• an object just sits there
• a moving object speeds up
• a moving object stops

Balanced forces can cause

• an object to speed up or slow down
• an object to stay still or move at a constant speed and direction

When was the ostrich going at a constant speed?

• Between 0 and 30 min.
• Between 45 and 60 min.
• Between 30 and 45 min.

this force is ___________ and there will be 

• unbalanced, no movement
• balanced, movement to the left
• balanced, no movement

This force is _____________ and there will be _________________

• balanced, movement to back left
• unbalanced, movement to the back left
• balanced, no movement

If all four forces are balanced, the plane will

• plummet to the ground
• fly faster and faster
• fly slower and slower
• fly at a constant speed and direction

If two spheres of different masses, but the same size are dropped at the same time

• they will hit the floor at the same time
• the larger mass will hit first
• the smaller mass will hit first

The more massive an object is...

• the harder it will be to get moving.
• The harder it will be to stop.
• the harder it will be to speed up.
• all of the above.

To measure speed, you need to know...

• distance covered and speed
• distance covered and time it took
• acceleration and distance
• direction and time

A _____ is a pull or a push.

• force
• friction
• gravity
• speed