From the moment when the train first touches the bridge, the (front end of the) train has to travel 180 meters until the back end leaves the bridge.
So how long does it take to travel 180 meters at a speed of 36 km/h?
You probably know that v = x/t. Where v is speed, x is distance and t is time.
We know v and x; we are looking for t. So bring t on one side of the equation and all other stuff on the other side (multiply by t and divide by v):
t = x/v
But we must be careful to handle the units correctly (i.e. not naively mixing meters and kilometers). Let us have a look at the speed unit.
36 km/h = 36000 m/h = 10 m/s (one hour has 60*60=3600 seconds)
t = 180m / 10m/s = 18s
So the train passes the bridge in 18 seconds.
PS:
Instead of converting v we could have converted x:
t = 0.18km / 36km/h = 0.005h
0.005 hours = 0.005*60 minutes = 0.005*60*60 seconds = 18 seconds
But I personally prefer the first way because I can do all the math in my head ;)
PPS:
Keep learning and try to solve such puzzles by yourself. Try hard!
s=d/ts= 100 / 12s= 8.33ms-1
14.5 meters per second is the speed. Speed means the amount of distance traveled in a certain amount of time. In your 14.5 meters per second your mouse deer is running 14.5 meters every 1 second. Therefore if no acceleration is occurring then at 2 seconds your deer will have run 29 meters. And at 3 seconds your deer would have run 43.5 meters.
Wow, 3 miles per second is running fast. At 1609.34 meters per mile, this converts to 4828.02 meters per second. Since 5 minutes is 300 seconds,this means you would run 1448406 meters in that time.
To do this you need to know:60 second in a minute60 minutes in an hour1609.344 meters in one mileNow first work out how far one would travel running at that speed in one minute, by finding how far you would have traveled in one second-100/9.7 = 10.30927835051546 meters /secondThen multiply by 60 to get distance traveled in one minute =10.30927835051546 * 60 = 618.5567010309278 meters / minute.Now multiply by 60 again to get the distance traveled in an hour618.5567010309278*60=37113.40206185567 meters / hourOK we now know that we would be running at a speed of 37113.40206185567 meters an hour. BUT we want the answer in miles an hour, so we have to divide this by the number of meters in a mile:37113.40206185567/1609.344=23.06 miles per hour.Compare this with the related answer for this question where the distance run was in Yards (which are shorter than meters - so you would be running slower)
Speed = (distance traveled) divided by (time to cover the distance) Speed = (50 meters) / (2 seconds) Speed = 50 meters per 2 seconds Speed = 25 meters per second
800 meters
Use the formula: Speed = distance / time. If you divide meters / seconds, the speed will obviously be in meters/second.
s=d/ts= 100 / 12s= 8.33ms-1
11.875 m/s
14.9129086 miles / hour
If you can run 800 meters in two minutes your average speed for the 800 meters is 14.91 miles per hour.
3.5 SECONDS
21.7 m/s
Neglecting air resistance . . .The acceleration of gravity is 9.8 meters (32.2 feet) per second2.After 5 seconds the marble's downward speed is (9.8 x 5) = 49 meters (160.8-ft) per second.Its average speed during the fall is (49/2) = 24.5 meters (80.4-ft) per second.The distance it falls is (24.5 x 5) = 122.5 meters (402-ft).
No, that's not correct.The acceleration of gravity means that for each second that passes, falling objects fallat a speed that's 9.8 meters per second fasterthan it was one second earlier.
14.5 meters per second is the speed. Speed means the amount of distance traveled in a certain amount of time. In your 14.5 meters per second your mouse deer is running 14.5 meters every 1 second. Therefore if no acceleration is occurring then at 2 seconds your deer will have run 29 meters. And at 3 seconds your deer would have run 43.5 meters.
speed is distance/time 23.7/54 = 0.44 m/sec