galileo increased the inclination of inclined planes. steeper inclines gave greater accelerations. ...
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Freefall
Galileo increased the inclination of inclined planes. Steeper inclines gave greater accelerations. When the incline was vertical, acceleration was
max, same as that of the falling object. When air resistance was negligible, all objects
fell with the same unchanging acceleration.
Acceleration
Falling under the influence of gravity only - with no air resistance
Freely falling objects on Earth accelerate at the rate of 10 m/s/s, i.e., 10 m/s2 (more precisely, 9.8 m/s2).
Free Fall
The greater the mass of the object… the greater its force of attraction toward the
Earth. the smaller its tendency to move i.e., the greater
its inertia.
Free Fall
So, the acceleration is the same.
It is equal to the acceleration due to gravity: 10 m/s2
(precisely 9.8 m/s2).
When acceleration is g—free fall Newton’s second law provides an
explanation for the equal accelerations of freely falling objects of various masses.
Acceleration is equal when air resistance is negligible.
Acceleration depends on force (weight) and inertia.
Free Fall
The velocity acquired by an object starting from rest is
Free Fall—How Fast?
So, under free fall, when acceleration is 10 m/s2, the speed is• 10 m/s after 1 s.• 20 m/s after 2 s.• 30 m/s after 3 s.And so on.
Velocity acceleration x time
The distance covered by an accelerating object starting from rest is
Free Fall—How Far?
So, under free fall, when acceleration is 10 m/s2, the distance is• 5 m after 1 s.• 20 m after 2 s.• 45 m after 3 s.And so on.
Distance (1/2) x acceleration x time x time
A. also 40 m/s.B. 45 m/s. C. 50 m/s.D. None of the above.
At one instant, an object in free fall has a speed of 40 m/s. Its speed 1 second later is
Free FallCHECK YOUR NEIGHBOR
A. also 40 m/s.B. 45 m/s. C. 50 m/s.D. None of the above.
Comment:We assume the object is falling downward.
At one instant, an object in free-fall has a speed of 40 m/s. Its speed 1 second later is
Free FallCHECK YOUR ANSWER
Terminal speed occurs when acceleration terminates
(when air resistance equals weight and net force is zero).
Terminal velocity same as terminal speed, with direction
implied or specified.
Non-Free Fall
A skydiver jumps from a plane. Weight is the only force until air resistance
acts. As falling speed increases, air resistance on
diver builds up, net force is reduced, and acceleration becomes less.
When air resistance equals the diver’s weight, net force is zero and acceleration terminates.
Diver reaches terminal velocity, then continues the fall at constant speed.
Non-Free Fall—Example
A. increases.B. decreases. C. remains the same.D. Not enough information.
As the skydiver falls faster and faster through the air, air resistance
Non-Free FallCHECK YOUR NEIGHBOR
A. increases.B. decreases. C. remains the same.D. Not enough information.
As the skydiver falls faster and faster through the air, air resistance
Non-Free FallCHECK YOUR ANSWER
A. increases.B. decreases. C. remains the same.D. Not enough information.
As the skydiver continues to fall faster and faster through the air, net force
Non-Free FallCHECK YOUR NEIGHBOR
A. increases.B. decreases. C. remains the same.D. Not enough information.
As the skydiver continues to fall faster and faster through the air, net force
Non-Free FallCHECK YOUR ANSWER
A. increases.B. decreases. C. remains the same.D. Not enough
information.
As the skydiver continues to fall faster and faster through the air, her acceleration
Non-Free FallCHECK YOUR NEIGHBOR
A. increases.B. decreases. C. remains the same.D. Not enough information.
As the skydiver continues to fall faster and faster through the air, her acceleration
Non-Free FallCHECK YOUR ANSWER
CommentIf this question were asked first in the sequence of skydiver questions, many would answer it incorrectly. Would this have been you?