# Physics

posted by Richard

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?

1. drwls

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.

## Similar Questions

1. ### Science

I have some equations that I would like checked. Thanxs! 1. An automobile starts from rest and accelerates at 3m/s2 for 4 seconds. How fast is it going after acceleration?
2. ### calculus

X. An automobile with seven years of use has a commercial value of \$34057.7, but five years ago its value was \$72250. If the value of such automobile varies exponentially with the time. (36-41) 36.- What was the value of the automobile …
3. ### calculus

An automobile with seven years of use has a commercial value of \$34057.7, but five years ago its value was \$72250. If the value of such automobile varies exponentially with the time. (36-41) 36.- What was the value of the automobile …
4. ### Science-Physics HELP

A S.S. automobile travels N at 40 km/h and a P.A. automobile travels E at 50 km/h. Relative to the observer riding in the S.S. auto what are the x and y components of the velocity of the P.A. car?
5. ### Physics

At the instant a traffic light turns green, an automobile that has been waiting at an intersection starts moving forward with a constant acceleration of 2.00m/s(squared). At the same time a truck traveling with a constant speed of …
6. ### Physics

At the instant a traffic light turns green, an automobile that has been waiting at an intersection starts moving forward with a constant acceleration of 2.00m/s(squared). At the same time a truck traveling with a constant speed of …
7. ### physics

An automobile moving at a constant velocity of 15 m/s passes a gasoline station. Two seconds later, another automobile leaves the station and accelerates at a constant rate of 2 m/s^2 in the same direction as the 1st automobile. How …
8. ### physics

At the instant the traffic light turns green, an automobile that has been waiting at an intersection starts ahead with a constant acceleration of 2.10m/s2 . At the same instant, a truck, traveling with a constant speed of 15.1m/s , …
9. ### Physics

An automobile and a truck start from rest at the same instant, with the automobile initially at some distance behind the truck. The truck has a constant acceleration of 2.15m/s2 , and the automobile an acceleration of 3.47m/s2 . The …
10. ### physics

n automobile has a vertical radio antenna 1.40 m long. The automobile travels at 30.0 km/h on a horizontal road where Earth's magnetic field is 50.0 µT, directed toward the north and downward at an angle of 65.0° below the horizontal. …

More Similar Questions