In 2015, Shea-Z ran 1600 m in 9 minutes, in 2017 his speed was 160 m/min. In which year was Shea-Z's speed best?

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

Which is the best for showing percentages of different types of cars sold(gas hybrid , electric , other ) in the united states ?

Your target variable is δf, the magnitude of the difference in frequency between the waves emitted from the sonar device and the waves received by the device after reflecting off the whale. write an expression for δf in terms of the relevant frequencies using the subscript notation introduced above.