Why do we use simple machines?

Why do we sweat ?

Give two examples where we use wedges as simple machines.

Give two examples where we use wedges as simple machines.

Where do we use centrifugal machine ?

Why levers usually have a greater mechanical efficiency than other simple machines do?

Why do we use calorimeters made of copper for calorimetric purpose ?

When analyzed, most complicated machines are found to consist of a combination of various simple machines. Which machine below is NOT a simple machine?

When analyzed, most complicated machines are found to consist of a combination of various simple machines. Which machine below is NOT a simple machine?

Why do we use ball-bearings?