giving a bridge that was 5.0 m long has been washed out and road is level on both sides but the road on the far side is 2.0 m lower than road on starting side.
2006-10-01 17:33:14 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Since there is only horizontal speed of the car, there is no initial vertical velocity. Hence:
h=1/2*g*t^2
t=0.63 seconds at g=10 m/s^2
And, s=v*t
v=s/t; s is horizontal distance
v=5/0.63
v=7.9 m/s
Therefore, the speed of the car should be AT LEAST 7.9 m/s.
2006-10-01 18:33:56 · answer #1 · answered by mekaban 3 · 0⤊ 1⤋
To solve this problem calculate the time it takes an object (accelerating uniformly due to gravity at a rate of -9.81 m/s^2) to fall 2 meters....this is the maximum amount of time the car has to cross the 5 m stream.
d = 1/2 at^2
where d is the distance traveled, a is the rate of acceleration, and t is the time.
Use -2 m as the distance and -9.81 m/s^2 as the acceleration.
Now that you have calculated the time, find the minimum speed.
d = vt
where d is the distance, v is the velocity, and t is the time.
This time use 5 m as the distance and the time you calculated earlier as t.
Also, sometimes drawing a picture of the situation helps you better visualize the problem and makes it easier to solve.
2006-10-01 17:47:48 · answer #2 · answered by mrjeffy321 7 · 0⤊ 0⤋
umm 70 miles an hour at a 30 degree ramp can get a car across a stream 75 feet wide, or less...
2006-10-01 17:37:19 · answer #3 · answered by tonyma90 4 · 0⤊ 1⤋
mrjeffy32...got it right and the approach is correct.
if i were you though i would consider a couple of meters more ...in order to take into consideration the lentg of the car. at least til its rear wheel otherwise it would reach the other side but it will crash on it.
2006-10-01 18:06:53 · answer #4 · answered by Emmanuel P 3 · 0⤊ 0⤋
This problem is essentially the same as the problem posed at the source below. Check there for the complete answer.
2006-10-01 17:52:05 · answer #5 · answered by hfshaw 7 · 0⤊ 0⤋
To fall by 2m
t = sqrt(2*2/9.8)
So, velocity = 5/t.
2006-10-01 18:02:42 · answer #6 · answered by ag_iitkgp 7 · 0⤊ 0⤋
See: Dukes of Hazard.
2006-10-01 17:35:49 · answer #7 · answered by · 5 · 0⤊ 1⤋
i could have told you a few minutes ago, but the Duke boys just left
2006-10-01 17:35:52 · answer #8 · answered by bad kitty 3 · 0⤊ 1⤋
depends on weight of car and width of stream
2006-10-01 17:40:46 · answer #9 · answered by afsm666 3 · 0⤊ 2⤋
stop cheating, and LEARN PHYSICS! too many questions and not enough answers on Yahoo Answers!
2006-10-01 17:41:29 · answer #10 · answered by abcdgoodall 4 · 0⤊ 1⤋