Question

heavier bodies needs greater initial effort to put them in motion. give reason

Answer 1

Due to its greater mass it needs greater initial effort .

Answer 2

To make a body move, you need to overcome the limiting friction which is the maximum value of static friction for a body.
Now, limiting friction= coefficient of friction x normal reaction
The normal reaction is basically the weight of the body on a horizontal surface. Thus in a heavier body since normal reaction is greater, friction is more and thus you need greater initial effort to move it.