Question

We can move our hand in air but to do the same through a wooden block we need a karrate expert

Answer 1

because this is due to momentum

Answer 2

Answer:

• Air is made up of particles that have least  inter molecular force and thus inter molecular distance will be maximum .
• But in case of wooden plank/ block,the particles have maximum  inter molecular force and thus least  inter molecular distance .
• This is a great reason that why we can move our hand in air but to do the same through a wooden block we need a karate expert.