A weight lifter lifts a 150 Kg barbell above his head from the floor to a height of 2m. He holds the barbell for 5 seconds. How much work does he do during that 5 second interval

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.

Explain why electric current cannot exist if a current doesn't have a voltage source.

Aball horizontally thrown from a cliff at 8m/s