Homework Help: Physics

Posted by Emma on Monday, August 27, 2007 at 2:44pm.

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?
-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)

Physics - bobpursley, Monday, August 27, 2007 at 4:35pm
3. Change 30km/hr to m/s
30km/hr*1hr/3600sec*1000m/km

then
distance=vi*t + 1/2 at^2
Physics - bobpursley, Monday, August 27, 2007 at 4:36pm
4. You need to work the units. Chang 30km/hr to meters/second. Then work it, keeping the units in the problem until you find out what your answer is, numerically, and the units.
Physics - Emma, Monday, August 27, 2007 at 10:19pm
I am still not understanding. Like for number 3, this is as far as I got 30km/36000000. Then for number 4, would it be similar as to number 3? Also, did I get number 1 correct?

Answer this Question

Related Questions

Physics - Could you please check my answers and units.Also, help me with 3 and 4...
Science - I have some equations that I would like checked. Thanxs! 1. An ...
Physics - Having trouble determ the formulas for the follow problems. 2. If an ...
Physics - An automobile accelerates from rest at 2.4 m/s2 for 29 s. The speed is...
physics - 1.The speed of a train increased from 15 mi/hr to 25 mi/hr in a ...
physics - An automobile accelerates from rest at 1.3m/s^2 for 19s. The speed is ...
Physics - An automobile and train move together along parallel paths at 31.6 m/s...
physics - 1)Top-fuel drag racers are able to uniformly accelerate at 12.3 m/s2 ...
Physics - A speedboat starts from rest and accelerates at 2.689x10^0 m/s2 for 6....
Physics - A tortoise and hare start from rest and have a race. As the race ...

For Further Reading

First Name:
School Subject:
Answer: