Question

class 11 physics motion in a plane numerical...​

Answer 1

Answer:

A train running at the speed of 60 km/hr. It crosses a certain pole that is in the way in 9 seconds. What is the length of the train?

We have the speed of the train = 60 km/hr. We have to convert it into m/s. Let us see the trick to convert km/hr to m/s:

1km/1h = 1×(1000/60×60) = 1×(5/18) m/s.

Therefore if the speed is ‘x’ km/hr then we can change it to m/s by multiplying x with 5/18. Let us do it for the current example.

We have the speed of the train = 60 km/hr or 60×(5/18) = 50/3 m/s.

Therefore in 9 seconds, the train will cover a distance = speed×time

In other words, we have the Distance = (50/3 m/s)×9 = 150 m.

Answer 2

refer to attachment

hope this will help u.