Then, the reaction does not have any kinetic energy
Answer:
d) the amount of work is the same whether the bag is moved all at once or in two stages, provided the total height lifted is the same in either case.
Explanation:
While moving the bag to the shelf in one shot we can say that the total work done is given as
here we know that
2H = total height raised by the bag
now when we raise the bag to first shelf and then move it to next shelf
then we will have
![W = W_1 + W_2[tex][tex]W = mgH + mgH](https://tex.z-dn.net/?f=W%20%3D%20W_1%20%2B%20W_2%5Btex%5D%3C%2Fp%3E%3Cp%3E%5Btex%5DW%20%3D%20mgH%20%2B%20mgH)
so the correct answer will be
d) the amount of work is the same whether the bag is moved all at once or in two stages, provided the total height lifted is the same in either case.
Answer:
D. Test a cell phone's reception in the exact same location under various atmospheric conditions
Explanation:
Components of an experiment:
Independent variable:
A manipulated variable, in an experiment or study, whose presence or degree incurs a change in the dependent variable.
Dependent variable:
A variable which is being studied in the experiment and is supposed to change with respect to the independent variable.
Control variable:
Control variable includes the variables which are of no concern in the experiment and must be constant so that they do not interfere with the results of the experiment. Change in control variable might affect the results of an experiment.
In Anna's experiment, the independent variable is the atmospheric conditions. The dependent variable is cell phone reception that will change according to the atmospheric conditions. All other things related to the experiment are control variables like cellphone, location of the cell phone. Both of these must stay constant to collect the best data.
Hence, the best option is D.
