a ball of mass 0.25kg moves on frictinless horizontal floor and hits a vertical wall with speed 5m/s . the ball rebound with speed 40m/s. if the ball was in contact with the ball for 0.150 seconds, then the average force that acts on the ball is

What type of questions asked from the lesson of magnetic effect of electric current 

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

What are the main components of our environment? Explain each of them briefly.

What are examples of hydrotropism plants?