Posted by **Richard** on Saturday, May 29, 2010 at 2:53am.

Having trouble determ the formulas for the follow problems.

2. If an automobile travels at 30 km/hr. for 2 hours, how far does it go?

60 km

3. At time = 0 an automobile already traveling at 30 km/hr. accelerates at 3m/s2 for 2 seconds. During these two seconds, how far does it go?

4. An automobile is traveling at 30 km/hr. It accelerates at 3 m/s2 until it has covered 100 meters.. What is its new velocity?

- Physics -
**drwls**, Saturday, May 29, 2010 at 5:32am
Let D = distance travelled and Vo be the initial velocity, and a be the acceleration

2. D = Vo * t (no acceleration; V remains Vo)

3. D = Vo*t + (1/2) a t^2

Vo = 8 1/3 m/s ; answer will be in meters

4. Vfinal^2 = Vo^2 + 2 a D

Vfinal = Vo + a t,

but you need to solve for t to use the second formula. The two formulas are consistent.

## Answer this Question

## Related Questions

- Science - I have some equations that I would like checked. Thanxs! 1. An ...
- physics - At the instant the traffic light turns green, an automobile that has ...
- Science-Physics HELP - A S.S. automobile travels N at 40 km/h and a P.A. ...
- Physics - At the instant the traffic light turns green, an automobile that has ...
- physics - An automobile moving at a constant velocity of 15 m/s passes a ...
- Physics - In a particular crash test, an automobile of mass 1295 kg collides ...
- physics help - A 1100 kg automobile is at rest at a traffic signal. At the ...
- calculus - An automobile with seven years of use has a commercial value of $...
- calculus - X. An automobile with seven years of use has a commercial value of $...
- Physics - At the instant a traffic light turns green, an automobile that has ...