- #1
keevo
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1. Homework Statement
A train has a mass of 5.77E+6 kg and is moving at 99.4 km/hr. The engineer applies the brakes, which results in a net backward force of 1.11E+6 N on the train. The brakes are held on for 26.9 s.
What is the new speed of the train?
How far does it travel during this period?
mass of train: 5,770,000 kg
speed of train: 99.4 km/hr (i converted it to m/s and got 27.611 m/s)
Backwards net force of: 1,110,000 N
Brakes held for: 26.9 s
2. Homework Equations
f=ma?
V=Vo+at?
X=Xo+(Vo)(t)+.5at^2?
3. The Attempt at a Solution
I am fairly new to physics and don't really know what I'm doing, anyways...first i used f=ma
and got a=.192 then i used that in the second equation and got V=1,110,005.165 N and then I plugged that into the third equation and got 29859069.4666 M but it said i was wrong :/.
Can someone please guide me through this problem? it would be much appreciated
-Thanks in advance!
Ok, so i tried it again and i was confident that i was correct.
i used f=ma to get a=.192
i then used a in the second equation ( V=27.611+.192(26.9)) to get a Velocity of 32.7758
i then used the 3rd equation to get a distance of 812.20246 m but it said it was wrong again.
can you help me clarify or show me where i went wrong?
Thanks
A train has a mass of 5.77E+6 kg and is moving at 99.4 km/hr. The engineer applies the brakes, which results in a net backward force of 1.11E+6 N on the train. The brakes are held on for 26.9 s.
What is the new speed of the train?
How far does it travel during this period?
mass of train: 5,770,000 kg
speed of train: 99.4 km/hr (i converted it to m/s and got 27.611 m/s)
Backwards net force of: 1,110,000 N
Brakes held for: 26.9 s
2. Homework Equations
f=ma?
V=Vo+at?
X=Xo+(Vo)(t)+.5at^2?
3. The Attempt at a Solution
I am fairly new to physics and don't really know what I'm doing, anyways...first i used f=ma
and got a=.192 then i used that in the second equation and got V=1,110,005.165 N and then I plugged that into the third equation and got 29859069.4666 M but it said i was wrong :/.
Can someone please guide me through this problem? it would be much appreciated
-Thanks in advance!
Ok, so i tried it again and i was confident that i was correct.
i used f=ma to get a=.192
i then used a in the second equation ( V=27.611+.192(26.9)) to get a Velocity of 32.7758
i then used the 3rd equation to get a distance of 812.20246 m but it said it was wrong again.
can you help me clarify or show me where i went wrong?
Thanks