Physics (8) Flashcards
What is Newton’s First Law?
An object at rest will remain at rest and an object in motion will stay in motion unless acted upon by and unbalanced or outside force
What is Newton’s First Law of Motion also called?
The Law of Inertia
What is inertia?
The tendency of an object to resist a change in motion. Large masses require more force to change and smaller masses require less force to change.
How do seatbelts demonstrate Newton’s First Law?
When a car is driving, it is in motion and so the occupant(s) are also in motion. In the case of an accident, the car in motion is acted on by an outside or unbalanced force. The car is abruptly stopped but the occupant(s) inside are still in motion.The seat belt restrains them and acts as an outside force to keep them safe and from being ejected from a vehicle.
Take a position on Seat belts on School Buses
Pick a stance and defend your answer
Sample Answers:
yes: seat belts on school buses provide less driver distraction with students buckled in. Seating children may also reduce bullying. Seat belts also promote a habit to wearing a seat belt any time one gets inside a vehicle.
no: school buses already have an excellent safety record, therefore, seat belts are not necessary. Seat belts for students on every bus for the district also costs quite a bit. Just by implementing a seat belt rule does not mean that they will be used. Making a rule may also make students just want to not wear a seat belt even more than before.
When will an airbag deploy?
when the vehicle rapidly decelerates
Force
a push or pull
formula for calculating speed
distance/time
formula for calculating distance
speed x time
formula for calculating time
distance/speed
formula for calculating acceleration
change in velocity/time
what is the format when describing the force on an object in Force (Free-Body) Diagrams?
F kind, an object, by agent
ex. F gravity, on person, by Earth
What are the steps in creating a force/ free-body diagram?
- shrink the system into a point
- use arrows (vectors) to demonstrate forces acting on the object
- the arrows will be larger or smaller depending on how much force is exerted
Ex. A log being pulled by train list forces on log: friction normal tension gravity draw log as a point and arrows with demonstrating all the forces
Airbags
- supplemental restraints-best in combination with seat belts
- air bags deploy when the sensors detect deceleration
- air bags rapidly decelerate when a collision occurs.
equation for speed
distance/time
