How to convert from km/hr^2 to m/s^2

[98.40_for_sure]

anyone got a spare 10 seconds to explain this supposedly easy as question to me
the question has i) and ii)
i) is answer in km/hr^2 (the answer is 12960)
ii) same but express in m/s^2 (stuck!!)

thanks for any help

[Whatlol]

anyone got a spare 10 seconds to explain this supposedly easy as question to me
the question has i) and ii)
i) is answer in km/hr^2 (the answer is 12960)
ii) same but express in m/s^2 (stuck!!)

thanks for any help

what you converting into km/hr^2 tho...

[98.40_for_sure]

its a SUVAT question
where they give you U(km/hr) V(km/hr) T(sec)

so to find out km/hr^2 i used V = U + AT but first i converted T into hr by x360

i dunno how to explain it... ill just type the question out

A car accelerates uniformly from 5 km/hr to 41 km/hr in 10 seconds. Express the acceleration in i) km/hr^2 ii) m/s^2

[Edmund]

5km/h = 5000m/h = 5000m/3600s

Therefore 1s = 1.389m i.e. 1.389m/s

[98.40_for_sure]

the answer surprisingly is... 1m/s^2
i have no idea how you go from 12960 km/hr^2 to 1m/s^2

the worked solution just says x(1/12960)

[Edmund]

41km/h = 11.4m/s

(11.4-1.4)/10s = 1m/s^2

[Whatlol]

the answer surprisingly is... 1m/s^2
i have no idea how you go from 12960 km/hr^2 to 1m/s^2

the worked solution just says x(1/12960)

Im not sure how they did that but i know how to do it another way.

simply convert 5km/h into m/s which will become 1.38m/s now do same for 41km/h which will become 11.38m/s
now acceleration is equal to change in velocity over time so 11.38-1.38 =10 and then devide that by 10 which is 10/10 = 1m/s^2

[shinny]

[98.40_for_sure]

ahhhh yes shinny's way works
i did the same but i forgot to square it
i did 12960000/60^2 m/s^2

thank you guys!

[jimmy999]

I'll show you a little trick we do in my engineering subject to convert units.

Start off with something in . Write it out as a fraction as so,

If we wanted to convert from km to m, we use unity brackets to multiply the units by effectively 1. We notice that there are 1000m in 1km. Hence we write it as;

This eliminates the km unit. We know that there are 3600s into 1 hour so we can write

Hence

Sometimes though you'll get confused on which part of the fraction to put which unit. Basically if the unit you want to eliminate, such as km is on the top, then first write 1km on the bottom, then 1000m on the top. It will be very useful in other problems you do so you get less confused and make less mistakes

[fady_22]

I just use this for conversion between kmh-1 and ms-1: to get from ms-1 to kmh-1, multiply by 3.6. To get from kmh-1 to ms-1, divide by 3.6. Easy.

[/0]

I just use this for conversion between kmh-1 and ms-1: to get from ms-1 to kmh-1, multiply by 3.6. To get from kmh-1 to ms-1, divide by 3.6. Easy.

This. And if you can't remember whether to multiply or divide, note that the value in km/h is always greater than the value in m/s.

[98.40_for_sure]

yeah its just when they chuck in a square'd or something that it becomes a bit confusing

[madoscar65]

Another way is, if you do physics, acceleration is a=(v-u)/t. a= 41-5/10 =3.6km/h^2 and to convert that to m/s^2 you simply divide 3.6 which is 1m/s^2

[Hutchoo]

I just use this for conversion between kmh-1 and ms-1: to get from ms-1 to kmh-1, multiply by 3.6. To get from kmh-1 to ms-1, divide by 3.6. Easy.

This. And if you can't remember whether to multiply or divide, note that the value in km/h is always greater than the value in m/s.

yeah, x3.6 or devide 3.6.