during a snowball fight, two balls with masses 0.4 and 0.6 kg collide head on and form a single mass. each snowball had an initial velocity of 15 m/s. what is the speed of the mass, immediately after collision?

The graph shows a trend in an ecosystem over time caused by increased pollution in the region. what can you conclude from the graph? a. there’s lower biodiversity among birds. b. there’s a higher reproductive rate among birds. c. there’s a significant decline in the number of producers. d. other types of animals were unaffected by pollution.