Physics
posted by Emma on .
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?
I got 12 m/s
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?
I got 12 m/s
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?
 6030 (not sure about units)

3. No. distane= vi*t + 1/2 a t^2
I will be happy to critique your work. Be certain to change km/hr to m/s
4. No. vf= sqrt (vi^2 + 2*a*d)
be certain vi is in m/s units.
I will be happy to critique your work or thinking