Answer:
The force is 
Explanation:
We can apply the following expression

To find the area of rectangular tent wall:

Now to find the force:



Answer:

Explanation:
As we know that train is initially moving with the speed

now we know that

now the final speed of the train when it crossed the crossing


now we can use kinematics here



Now the time to cross that junction is given as



Answer:If an object's speed changes, or if it changes the direction it's moving in,
then there must be forces acting on it. There is no other way for any of
these things to happen.
Once in a while, there may be a group of forces (two or more) acting on
an object, and the group of forces may turn out to be "balanced". When
that happens, the object's speed will remain constant, and ... if the speed
is not zero ... it will continue moving in a straight line. In that case, it's not
possible to tell by looking at it whether there are any forces acting on it
Answer:

Explanation:
Path difference due to a transparent slab is given as

here we know that

now total shift in the bright fringe is given as

Also we know that the fringe width of maximum intensity is given as

now we have

now the shift is given as

given that the shift is

here we have

now plug in all values in it


