As an object accelerates to a speed close to the speed of light, which of the following stays the same? a speed of light b length of the object c how object and observer experience time d rate of time passage

Option A, speed of light.

Explanation: As the object reaches the speed of light, the length of the object will contract, this is called the Lorentz contraction. Also, the object will experience the time slower than if it were at rest, so an observer and the object will experience the time in a different way, and because of this the "rate of time passage" changes, so we already discarded option B, C, and D.

Now, the speed of the light is invariant, it is the same in any system and is a "physical constant", so it would not change, then the correct option is A.

  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