Speed & Velocity
You're running a marathon and it takes you 14 seconds to run 42 meters. What is your speed?
3 m/s
What are the three types of acceleration?
Speeding up, slowing down, changing direction
What is the formula for speed?
Speed = distance / time
A box has a net force of 0 Newtons. Are the forces acting on it balanced or unbalanced?
Balanced
What day is the quiz?
Tomorrow!
A car travels northbound with an average speed of 10m/s. Describe its velocity.
10m/s northbound
A person is walking 2m/s down a straight hallway, are they accelerating?
No
What is acceleration due to gravity?
10m/s2
Kevin and Lucy are playing tug of war. Kevin exerts 45 N on the rope to the left and Lucy exerts 43 N on the rope to the right. What is the Net force acting on the rope?
2 N
Net force is always written in which unit?
Newtons
You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel?
2m/s
A person is running around a track in a large oval. They are running at a constant speed of 3 m/s. Are they accelerating?
Yes
To find the net force when two forces are going in the same direction, you
Add them together
Bob and Sam are moving a couch. Bob exerts 25 Newtons of force to push the couch to the right. Sam is exerting 25 Newtons of force to pull the box to the right. What is the net force?
50 Newtons
If two forces go in the opposite direction, to calculate the net force you
subtract
How much time will it take for a bug to travel 5 meters across the floor if it is traveling at 1 m/s?
5 seconds
A car slowly stops at a stop sign. What type of acceleration is this?
Negative acceleration
meters, grams, and seconds.
A car is moving at a constant velocity down a busy highway. Is the force balanced or unbalanced?
Balanced
What are the four types of forces we talked about?
contact force, friction, gravity, electromagnetic
A plane travels 450,000 meters to the east in 9000 seconds. What was its velocity?
50 m/s eastbound
A person is walking 2m/s. After 2 seconds they speed up to 4m/s. What is their acceleration?
4-2/2 = 1m/s
What is the formula for acceleration?
final v - initial v / time
A ball is accelerating at 5m/s. Is the force balanced or unbalanced?
Unbalanced
A man is walking down the aisle of a train and says he is moving 2 m/s. A man on the platform says no, you're moving 72 m/s. Why do they have different answers?
Different reference points