Question

Direction: Answer the following problem sets. Please include what is the given, asked, formula, solution and final answer with unit.
This should be the format of your answer:
Ex. Given: distance = 500 m/s
time = 10 s
Asked: speed
Formula: d/t
Solution: 500 m/10 s
Answer: 50 m/s

1. A race car decelerates at 10 m/s2. If it is going at 60 m/s, how many meters will it take for the race car to stop?
2. The new Ferrari can accelerate from rest to 100 km/hr in 5 seconds. What is the average acceleration of the car in m/s2?
3. A car starts from a stoplight and is traveling with a velocity of 10 m/sec east in 20 seconds. What is the acceleration of the car?
4. A ball is rolled at a velocity of 12 m/s. After 36 seconds, it comes to a stop. What is the acceleration of the ball?

Answer 1

Answer:

7.5s

1.6666 repeating or 1.67 m/s²

Step-by-step explanation:

the equation you have to use is Vfinal=Vstart+acceleration•time

(I'm gonna simplify to Vf=Vs+at)

so you gotta rework it for the two equations

for the first equation you need time so take Vf=Vs+at and subtract Vs on both sides to get Vf–Vs=at

then divide acceleration on both sides to get t=(Vf–Vs)/a

for the second problem equation need the equation a=(Vf–Vs)/t (just divide time on both sides instead of acceleration)

so you the plug in

(I don't put the units in to the problem unless needed)

1. t=(Vf–Vs)/a to t=(0–30)/-4.0

t= -30/-4.0

t=7.5 seconds

2. a=(Vf–Vs)/t to a=(10–0)/6.0

a= 10/6.0

a= 1.67m/s²

(I'm assuming the that for number two they started at rest so it would be 0m/s for velocity start)