Chapter 3 Forces & Newton’s Laws. Forces. Force —a push or pull that one body exerts on another Forces can be shown as vectors Vector –an arrow showing the direction and amount of force. The longer the arrow, the larger the force. Forces cont’d.
Shooting Objects at RestThe object’s inertia causes it to remain still even when a bullet passes through it.
Friction:A force that opposes motion between two surfaces that are touching each other
The amount of friction is dependent upon
Type of Surfaces
Amount of force pressing the surfaces together
F = m × a
F = ma becomes W=mg
Weight = mass × gravitational acceleration
g on Earth is 9.8m/s2
SI Unit for Weight = Newton (N)
Weight can change with a change in location.Weight vs. Mass
Real World/space station & centripetal force
7 min 50 sec
dropping objects on the moon 3 3 min
An object shot horizontally & one dropped from the same height at the same time, will hit the ground at the same time.
Juggling & Projectile Motion2minmin
Mythbusters Bullet Fired and Dropped
Where should the zookeeper aim?
Taking Gravity into effect The zookeeper aims above the monkey
Does the speed of the banana change the effect?
The zookeeper aims at the monkey and shoots the banana very fast
The zookeeper aims at the monkey, yet shoots the banana very slow.
ZOO in SPACE
In a low gravity environment, where should the zookeeper shoot the banana?
Equal in size
Equal in time.
occur at EXACTLYthe same time.
In Newton’s 3rd Law, “opposite” means:
Opposite in direction
forces are EXACTLY180oapart in direction.“Equal & Opposite”
Bowling ball hits the pin to the left.
Pin hits the bowling ball to the right
Bozeman science 3rd law 6 minutes
Also: find 3rd law action reaction pairs: how to writeWriting Action Reaction Statements