
#1
Nov706, 05:02 PM

P: 208

Okay, Can someone do these for me so I can understand acceleration:
My car can reach a maximum speed of 150km/hr. And my car can acclerate at 5km/hr^{2}. How long will it take for my car to reach 150km/hr from rest. I know acceleration is the velocity of the velocity and the eqn for acceleration but I don't know how it works. 



#2
Nov706, 06:27 PM

Mentor
P: 40,875

a = (Vf  Vi)/t or Vf = Vi + at Plugging in your values and solving for time gives: t = 30 hr. 



#3
Nov706, 06:35 PM

P: 208

So in 1 hour, it went from 0km/hr to 5km/hr. And in the 2nd, it went to 10km\hr. In 5 hours, how much distance did it cover?




#4
Nov706, 06:47 PM

Mentor
P: 40,875

Questions on Acceleration
At the end of 5 hours, its speed will be 25 km/hr. During those 5 hours the average speed, since it started from rest, is 12.5 km/hr. Use that speed to calculate the distance: 62.5 km.




#5
Nov706, 06:58 PM

P: 208

1hr=5km/hr
2hr=10km/hr 3hr=15km/hr 4hr=20km/hr 5hr=25km/hr 5+10+15+20+25=75 75/5=15km\hr at the end of 5hr, it will be 15km\hr x 5hr, which is 75km. Why is the answer 62.5km? 



#6
Nov706, 07:09 PM

Mentor
P: 40,875

If that's what you're doing, start by working out the distance traveled in the first hour. Hint: It's not 5 km. (I'm going to split off this discussion into a separate thread in "Intro Phys".) 


Register to reply 
Related Discussions  
Force, Mass, and Acceleration Questions  Introductory Physics Homework  5  
More constant acceleration questions  Introductory Physics Homework  1  
need help w/ centripetal acceleration lab questions  Introductory Physics Homework  3  
Acceleration questions  Introductory Physics Homework  2  
Need help with centripetal acceleration questions  Introductory Physics Homework  2 