Aloaded 355 kg toboggan is traveling on smooth horizontal snow at 4.00 m/s when it suddenly comes to a rough region. the region is 6.60 m long and reduces the toboggan's speed by 1.00 m/s . what average friction force did the rough region exert on the toboggan?

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

The two required components for a generator are

An ideal otto cycle has a compression ratio of 10.5, takes in air at 90 kpa and 40°c, and is repeated 2500 times per minute. using constant specific heats at room temperature, determine the thermal efficiency of this cycle and the rate of heat input if the cycle is to produce 90 kw of power.