Correct matching:
1 acceleration -->
rate of change in velocity, which is the change in velocity divided by the change in time
2. speed --> the rate at which an object changes position when traveling in a certain direction
4. gravity --> force of attraction between all masses in the universe
5. Inertia --> an object´s resistance to a change in motion
3. friction --> force of resistance acting between objects in contact and tending to dampen their motion
6. velocity --> the rate at which an object changes position
 
        
             
        
        
        
Answer:
1. 3 m
2. 27 s
Explanation:
1. "A car traveling at +33 m/s sees a red light and has to stop.  If the driver can accelerate at -5.5 m/s², how far does it travel?"
Given:
v₀ = 33 m/s
v = 0 m/s
a = -5.5 m/s²
Unknown: Δx
To determine the equation you need, look for which variable you don't have and aren't solving for.  In this case, we aren't given time and aren't solving for time.  So look for an equation that doesn't have t in it.
Equation: v² = v₀² + 2aΔx
Substitute and solve:
(0 m/s)² = (33 m/s)² + 2(-5.5 m/s²) Δx
Δx = 3 m
2. "A plane starting from rest at one end of a runway accelerates at 4.8 m/s² for 1800 m.  How long did it take to accelerate?"
Given:
v₀ = 0 m/s
a = 4.8 m/s²
Δx = 1800 m
Unknown: t
Equation: Δx = v₀ t + ½ a t²
Substitute and solve:
1800 m = (0 m/s) t + ½ (4.8 m/s²) t²
t ≈ 27 s
 
        
             
        
        
        
Answer:
1/8 = (1/2)^3
This implies the sample has decayed for 3 half lives
3 * 5730 yrs = 17,200 years