Inertia 3.2 Questions Flashcards
Which has the most inertia, a truck, desk, or feather?
truck=most mass= most inertia
feather=least mass=least inertia
why should you not sit in the back of a pickup truck while it is moving?
when the truck accelerates forward, your body gets pushed back (inertia)–> you collide into the back of the truck and get injured
explain why its hard to get a car moving on slippery ice
To keep the car moving at a constant velocity,
the net force on the car in the direction of motion
must be zero.
The large applied force by the engine of the car has to be cancelled by the friction of the road surface to maintain a constant velocity.
Slippery ice surface gives almost no friction so it is
hard to get the car moving on ice.
Why shouldn’t you put objects onto the ledge of a car between the rear windshield and rear seat
When the car suddenly accelerates forward, the
object on the ledge of the car between the rear
windshield and the rear seat will be bounced back
toward the rear windshield due to inertia.
Sharp and heavy objects may crack the windshield
During liftoff, why are astronauts placed hor. in the capsule rather than vertically?
-during liftoff, they’ll feel a downward push(inertia)
-vertically, it will compress them
-easier on the body to be hor.
If a car suddenly stops but keeps moving in a straight line, will a seatbelt or headrest help?
seatbelts help since the body will be pushed fwd due to inertia
headrests won’t help since the head is moving fwd not back
If a car suddenly speeds up but keeps moving in a straight line, will a seatbelt or headrest help?
seatbelt won’t help because it’s your head snapping back
headrest prevents head from snapping all the way back due to inertia
Why does the normal force have to be equal in magnitude to the force of gravity for an object to remain at rest on a hor. surface?
so that they can cancel each other to give a net force of zero on the object
