Accelation problem, how do I change units (km/h to m/s)?

In summary, the world's first supersonic car, ThrustSSC, accelerated from rest to 1000km/h in 16 s. Its acceleration in m/s is 62.5 km/h every second.
  • #1
pillar
35
0
I made a mistake I meant km/h to m/s^2.
1. ThrustSSC, the world's first supersonic car, accelerates from rest to 1000km/h in 16 s. What is its acceleration in m/s?
2.a=v/t = v-v0/t-0
3. I'm not sure how to change units (Professor didn't show me.), so can you please now all the work to the problem? Thanks in advance.
 
Last edited:
Physics news on Phys.org
  • #2
Use dimensional analysis, first you should convert the speed from km/h to m/s. Whats the conversion between kilometers and meters? And hours to seconds? The first is easy, 1000m = 1km. The second is 1h = 3600s. Simply multiply the speed by the correct conversion factors to get your result.
 
  • #3


Pengwuino said:
Use dimensional analysis, first you should convert the speed from km/h to m/s. Whats the conversion between kilometers and meters? And hours to seconds? The first is easy, 1000m = 1km. The second is 1h = 3600s. Simply multiply the speed by the correct conversion factors to get your result.

Wait I'm sorry I meant km/h m/s2.
 
  • #4


pillar said:
Wait I'm sorry I meant km/h m/s2.
Do as Pengwuino says: First convert km/h to m/s.

Hint: 1 km = how many meters? 1 hr = how many seconds? Substitute!
 
  • #5


Doc Al said:
Do as Pengwuino says: First convert km/h to m/s.

Hint: 1 km = how many meters? 1 hr = how many seconds? Substitute!

1 km=1000m 1 hr = 3600s I'm not sure how to convert it to m/s^2 Unless I'm suppose to square the 3600, right?
 
  • #6


pillar said:
1 km=1000m 1 hr = 3600s I'm not sure how to convert it to m/s^2 Unless I'm suppose to square the 3600, right?

So this guy accelerated by 1000km/h in 16 s. That's 62.5 km/h every second. What's 62.5 km/h in m/s?
 
  • #7
You don't want to divide by the time it took him to reach that speed in the first step. If you did, you'd have something with units km/(h*s) which isn't what you want. Put your answer into m/s and then you can divide by the time in seconds which will result in a m/s^2 answer. Fill in the blanks here:

[tex]\[
\frac{m}{s} = \frac{{km}}{h}*\frac{{1h}}{{?s}}*\frac{{?m}}{{1km}}
\]

[/tex]
 
  • #8
I understand now velocity is m/s, plugging it into a formula (say acceleration = change in velocity/time) time=s velocity= m * s^-1 m * s^-1 * s^-1=m/s^-2=m/s^2

Thanks all.
 

1. What is acceleration and why is it important?

Acceleration is the rate at which an object's velocity changes over time. It is important because it helps us understand how quickly an object is speeding up, slowing down, or changing direction.

2. How do I calculate acceleration?

Acceleration can be calculated by dividing the change in an object's velocity by the change in time. The formula for acceleration is: a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

3. What are the units of acceleration?

The units of acceleration are typically measured in meters per second squared (m/s^2) in the metric system, or feet per second squared (ft/s^2) in the imperial system. This represents the change in velocity per unit of time.

4. How do I convert from kilometers per hour (km/h) to meters per second (m/s)?

To convert from km/h to m/s, you can use the conversion factor 1 km/h = 0.2778 m/s. This means that if you have a value in km/h, you can multiply it by 0.2778 to get the equivalent value in m/s.

5. Why is it important to know how to change units for acceleration?

It is important to know how to change units for acceleration because different situations may use different units, and being able to convert between them allows for easier comparison and understanding of data. It also allows for accurate calculations when solving problems involving acceleration.

Similar threads

  • Introductory Physics Homework Help
Replies
22
Views
938
  • Introductory Physics Homework Help
Replies
11
Views
792
  • Introductory Physics Homework Help
Replies
12
Views
736
  • Introductory Physics Homework Help
Replies
20
Views
948
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
800
  • Introductory Physics Homework Help
Replies
14
Views
793
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
Back
Top