Unbalanced Vs. Balanced Forces
What does it mean when force on an object are balanced?
The forces are equal and there is no change in motion.
What does "net force" mean?
The total force acting on an object after all forces are combined.
What is the formula for speed?
Speed = Distance/Time
What is the formula for velocity?
Velocity = Distance/Time
What is the formula for acceleration?
What happens to an object when the forced acting on it are unbalanced?
Its motion changes (it speeds up, slows down, or changes direction).
If two people push a box in the same direction, Person A with 5N and Person B with 3N, what is the net force?
8N in the direction they are pushing.
A student walks 20 meters in 10 seconds. What is their speed?
2 m/s
If a student runs 50 meters in 10 seconds, what is their velocity?
5 m/s
If a skateboard speeds up from 2 m/s to 6 m/s in 2 seconds, what is the acceleration?
(6-2)/2 = 2 m/s2
If a box has 10 N of force pushing left and 10 N pushing rights, what type of force is this?
Balanced Force
If one force pushes right with 10N and another pushes left with 4N, what is the net force and direction?
6N to the right.
Which unit is commonly used for speed in science class. m/s or cups/second?
m/s (meters per second)
True or False: Velocity and speed are the same thing
False - velocity includes directions, speed does not.
True or False: Acceleration only means an object is speeding up.
False - it can be speeding up, slowing down, or changing direction.
A toy car has 15N pushing forward and 5 N pushing backward. What is the net force, and is it balanced or unbalanced?
Net force = 10 N forward
Unbalanced
A box has 12N pulling left and 12N pulling right. What is the net force, and what type of force is this?
Net force = 0N
Balanced force (no motion change)
A bike travels 150 meters in 30 seconds. Calculate the speed.
5 m/s
A car travels north 120 km in 2 hours. What is its velocity?
60 km/h North
A car slows down from 20 m/s to 10 m/s in 5 seconds. What is its acceleration?
(10-20)/5 = -2 m/s2 (negative for slowing down)
Unbalanced (2N forward), the desk will move forward.
A student pushes a cart forward with 25N while friction pushes backward with 9N and another student pushes forward with 6N. What is the net force?
(25+6)-9=22N forward
A car travels 60 km in 1.5 hours. What is the speed? (Show steps if solving)
40 km/h
A rocket travels north 300 km in 2 hours. What is its velocity?
150 km/s
(12-0)/3 = 4 m/s2