Answer:
1.The rate of change of velocity is known as acceleration.Its SI unit is m/s^2
2.The lever in which the load is located between the effort and the fulcrum.If the load is closer to the effort than the fulcrum, then more effort will be required to move the load. For example-wheelbarrow,bottle opener etc .
3. in order to exert less pressure on the ground and prevent the building from sinking into the ground.
4.In a lightning protection system, a lightning rod is a single component of the system.