Asoccer ball is kicked from the ground with an initial speed of 20.1 m/s at an upward angle of 47.8˚. a player 53.0 m away in the direction of the kick starts running to meet the ball at that instant. what must be his average speed if he is to meet the ball just before it hits the ground? neglect air resistance.

3.95 m/s

Explanation:

Given

Initial velocity(u)

launch angle

Player is 53 m away

Range of projectile

R=41.02 m

so he need to run 53-41.02=11.98 m

Time of flight of projectile

T=3.03 s

thus average speed of boy

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =