Answer:
A scalar is a quantity that is fully described by a magnitude only. It is described by just a single number. Some examples of scalar quantities include speed, volume, mass, temperature, power, energy, and time.
Examples of scalar quantity are:
Distance.
Speed.
Mass.
Temperature.
Energy.
Work.
Volume.
Area.
Explanation:
please mark me as brainliest thank you 
 
        
             
        
        
        
Answer:
  v_f = 24.3 m / s
Explanation:
A) In this exercise there is no friction so energy is conserved.
Starting point. On the roof of the building
          Em₀ = K + U = ½ m v₀² + m g y₀
Final point. On the floor
          Em_f = K = ½ m v_f²
          Emo = Em_g
          ½ m v₀² + m g y₀ = ½ m v_f²
         v_f² = v₀² + 2 g y₀
          
let's calculate
         v_f = √(10² + 2 9.8 25)
         v_f = 24.3 m / s
 
        
             
        
        
        
Answer:
1/8 = (1/2)^3
This implies the sample has decayed for 3 half lives
3 * 5730 yrs = 17,200 years
 
        
             
        
        
        
Dipper effect of an oncoming train get louder as it approaches and sound diminishes as it goes away sound traveling
        
             
        
        
        
The only reasonable choice from this list is choice-A.