An airplane travels 70 miles per hour. The magnitude of the resultant velocity of the plane is 90 miles per hour, if it encounters a 20 mile per hour headwind.
True
False

True

Explanation:

This is simple subtraction. The force of opposite direction (wind) slows down the plane 20 mph which would result in the plane's velocity to be 70 mph. True is the correct answer.

  the unit of the measure =

explanation:

  the property that is quantified by the energy needed per of material to raise the temperature by one.

  si unit of energy = joule (j)

  si unit of temperature = kelvin (k)

  si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.