Two friends of different masses are on the playground. they are playing on the seesaw and are able to balance it even though their masses are different.

how are they able to balance on the seesaw?

1) they are able to balance torques due to gravity.
2) they are able to balance their respective energies.
3) all of these.
4) their densities are the same.
5) they are able to balance forces due to gravity.
6) they are able to balance their respective momenta.

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Six pendulums of mass mand length las shown are released from rest at the same angle theta from vertical. rank the pendulums according to the numberof complete cycles of motion each pendulum goes through perminute. a. l= 1m m=2kg b. l= 4m m=1 kg c. l= 2 m m= 2 kg d. l= 1 m m= 4 kg e. l= 2 m m = 4 kg f. l= 4m m = 4kg