Forces
A push or a pull
force
Why does a tissue paper fall down slower than a pencil?
there is more air friction that acts on the surface of the tissue paper, it also light enough to be affected by the air friction. (surface area relative to weight)
What has more momentum?
1000kg truck traveling 20 km/s
500kg car traveling 50 km/s
500kg car
Grip
hold, grabbing something
"I can see further because I have stood on the shoulder's of giants." What does this mean?
Newton made discoveries because he learned from many smart people before him.
"the force that pulls two objects toward one another, generally downward"?
gravity
You push a box that is 5kg at an acceleration of 2km/hour. How much force are you using?
10 Newtons
A ball on a table has 100J of potential energy. How much kinetic energy does it have if it falls off the table and is about to hit the floor?
100J kinetic energy
docked
stopped, parked (especially a boat or ship)
When trying to make the force smaller in an impact/collision, what is a factor that we try to extend?
length of time of impact
a force that acts in the opposite direction of an action when two things touch
friction
When you jump off a boat into the water, the boat moves back. Why is this?
Newton's 3rd law, actions have an equal reaction.
How do seatbelts protect a passenger?
1) objects stay in motion unless acted by an outside force
2) without a seatbelt, you will keep going forward when a car stops all of a sudden (collision)
3) seatbelts help you stop with the car
bulge
something sticking out
How did 2 astronauts get stuck on the International Space Station for 9 months?
You kick a ball. Explain the forces that are at work.
your foot pushes the ball.
the ball pushes your foot
gravity pulls it to the ground.
friction is slowing it down.
1) increase time that force is exerted on your body
2) spreads out the surface area that force is exerted on your body
conduct
to start doing something, like an experiment or activity
Why happens during a spring tide?
The sun and moon align, their gravity combines and makes the tidal range on earth greater.
an object that tends to resist change
intertia
Two students help push a large cart. Why might the cart not move? (3 reasons)
1) The cart is too heavy
2) They are pushing in opposite directions (balanced force)
3) There is too much friction on the floor
What are two designs in car that help a car be "crashworthy"?
1) hood can crunch/collapse/crumple over a longer period of time and distance
2) the safety cage (passenger seats) are strong and resistant to crumpling
swell
grow, increase in size
What has more friction on a gym floor, dry towel or moist paper towel?
Slightly moist, because it removes that dust that has less friction, the fibers swell and has more contact with a shoe.