I believe the correct answer is D
Put the object or material on a scale to figure out<span> its mass. 3. Divide the mass by the volume to </span>figure out the density<span> (p = m / v). You may also need to know </span>how to calculate<span> the volume of a </span>solid s<span>o use the formula</span>
If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
X-rays and gamma rays are the only electromagnetci waves with a shorter wavelength, gamma rays being the smallest. Hope this helps ;)
