Answer:
It takes the train 7.5 seconds to reach top speed
The train travels 112.5 meters before it reaches its top speed
Step-by-step explanation:
The Metro Rail makes a stop at NRG Stadium to pick up some Texans
fans after the game
After all the passengers board, the train accelerates at a rate of 4 m/s²
to a top speed of 30 m/s
We need to find the train takes how many seconds to reach the
top speed
Given is:
→ The train start from rest, then its initial speed u = 0
→ It acceleration a = 4 m/s²
→ Its top speed v = 30 m/s
To find the time we can use this rule;
→
→
seconds
It takes the train 7.5 seconds to reach top speed
Now we need to find how far the train travels before reaches top speed
We can use this rule;
→ v² = u² + 2as, where s is the distance
→ v = 30 m/s , u = 0 , a = 4 m/s²
Substitute these values in the rule
→ (30)² = 0 + 2(4) s
→ 900 = 8 s
Divide both sides by 8
→ s = 112.5 m
The train travels 112.5 meters before it reaches its top speed