Hello kiddio!
Most of the mass<span> of atom is in a dense positively charged </span>nucleus<span>. Most of the volume of an atom is in an empty space in which negatively charged electrons move around the </span>nucleus<span>.
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Have a nice day
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.
On the map red bands represent the earthquake
Answer:
Push and pull are both forces, but the difference is in their direction at which it is applied. If the force applied in the direction of motion of the particle then we call it push. If that force applied in the direction OPPOSITE to the motion of the particle then it it termed as pull
You can compare the velocity of the car, 60 mph, with the velocity that a mass would acquire when falls from certain height.
First, convert 60 mph to m/s:
60 miles/h * 1.60 km/mile * 1000 m/km * 1h/3600s = 26.67 m/s
Second, calculate from what height a body in free fall reachs 26.67 m/s velocity when hits the floor.
free fall => Vf^2 = 2g*H => H = Vf^2 / (2g)
H = (26.67m/s)^2 / (2*9.8 m/s) = 36.2 m
If you consider that the height between the floors of a building is approximately 3.6 m, you get 36.2 m / 3.6 m/floor = 10 floors.
Then, you conclude that the force of impact is the same as driving you vehicle off a 10 story building.
