Falling Objects Unit 3.1

Falling Objects On August 2, 1971, a demonstration was conducted on the moon by astronaut David Scott. He released a hammer and a feather both fell straight down and landed on a lunar surface at exactly the same moment.

https://www.youtube.com/watch?v=4mTsrRZEMwA

Falling Objects An object thrown or dropped in the presence of Earth’s gravity experiences a constant acceleration directed towards the center of the Earth. This acceleration is called free fall acceleration or the acceleration due to gravity.

Falling Objects Free fall acceleration is the same for all objects regardless of mass. This occurs in the absence of air resistance.

Falling Objects

Falling Objects The amount of time that passed between the first and second images is equal to the amount of time that passed between the fourth and fifth images. The picture, however, shows that the displacement in each time interval did not remain constant. Therefore the velocity was not constant. The tennis ball and the marble were accelerating.

Falling Objects

Falling Objects The value for free fall acceleration used is a = -g = - 9.81 m/s2 We will consider the direction of the free fall acceleration is considered to be negative because the object falls towards the Earth.

Acceleration Go to following website for animation: http://www.physicsclassroom.com/mmedia/kinema/acceln.cfm