Aracecar beginning at rest accelerates at a rate of 4.0 m/s2. it takes the car 21s to reach the end of the track. how long is the track in kilometers?

2.289 km

Explanation:

We can simply solve this by applying motion equations

where  

s - distance

u - initial velocity

a-acceleration

t - time

  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