"Two locomotives approach each other on parallel tracks. Each has a speed of v = 70 km/h with respect to the ground. If they are initially d = 7.5 km apart, how long will it be before they reach each other?"
2007-09-19 08:19:39 · 3 answers · asked by Brooke B 1 in Science & Mathematics ➔ Physics
Jennifer is wrong. You need to use their "closing speed" which is the sum of their two speeds, or 140km/h.
t = D /r = 7.5/140 = 0.0535714h [3 minutes 12.8 seconds]
2007-09-19 13:07:30 · answer #1 · answered by jsardi56 7 · 0⤊ 0⤋
you need to use the speed=distance divided by time formula.
v=d/t
where v= 70 km/hr,
d= 7.5 km,
and solve for t (time).
2007-09-19 08:33:47 · answer #2 · answered by Jennifer 3 · 0⤊ 0⤋
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2016-11-05 21:20:59 · answer #3 · answered by Anonymous · 0⤊ 0⤋