Science
posted by Emma .
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?
3m/s^2 / 4 = .75 m/s
2. If an automobile travels at 30 km/hr. for 2 hours, how far does it go?
d=(30 km/hr)(2 hr)= 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? (This one I don't understand)
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? (This one I don't understand)

Science 
manny
1. Multiply like in number two
2. Right
3. final velocity^2 = initialvelocity^2 + 2*acceleration*(distance traveled)
 Solve for distance traveled
4. use above equation and solve for final velocity
Respond to this Question
Similar Questions

Physics
Could you please check my answers and units. Thanxs! 1. An automobile starts from rest and accelerates at 3m/s2 for 4 seconds. How fast is it going after acceleration? 
Physics
Could you please check my answers and units.Also, help me with 3 and 4, I don't quite understand them. Thanxs! 1. An automobile starts from rest and accelerates at 3m/s2 for 4 seconds. How fast is it going after acceleration? 
physics please help!
A car driving along a straight road increases its velocity from 2.8 m/s to 9.7 m/s in 3 seconds. Calculate its acceleration in m/s^2 A skier in the Giant Slalom will accelerate at a constant 5.0 m/s^2 If she starts from rest, how fast … 
Physics
If a car starts from rest and travels for 5.0 seconds with a uniform acceleration of +1.5 m/s2. The driver then applies the brakes for 3.0 seconds, causing a uniform acceleration of  2.1 m/s2. a) Sketch the velocity vs. time graph … 
physics
Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 4.6 m/s2 for 4.4 seconds. It then continues at a constant speed for 8.5 seconds, … 
Physics
A tortoise and hare start from rest and have a race. As the race begins, both accelerate forward. The hare accelerates uniformly at a rate of 0.8 m/s2 for 4.4 seconds. It then continues at a constant speed for 13.5 seconds, before … 
physics with 6 questions
Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 3.3 m/s2 for 3.9 seconds. It then continues at a constant speed for 13.7 seconds, … 
Physics
Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 3.6 m/s2 for 4.5 seconds. It then continues at a constant speed for 7.3 seconds, … 
physics
Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 5.5 m/s2 for 4.9 seconds. It then continues at a constant speed for 6.7 seconds, … 
Physics
Car A is 12 m ahead of car B on a straight stretch of road. Car A starts from rest and accelerates away from B at 4.0 m/s2. Two seconds later B starts from rest and accelerates after A at 6.0 m/s2. How long will it take B to catch …