Aball is thrown upwards at an unknown speed. in a time of .5 second the ball has a height of 6 meters. what is the initial speed of the ball? what is the balls speed at a height of 6 meters? what would be the balls maximum height? (hint: you dont know the time to reach maximum height)

a)  Initial speed of the ball = 14.45 m/s

b) At height 6 m speed of ball = 9.55 m/s

c) Maximum height reached = 10.65 m

Explanation:

a)  We have equation of motion , where s is the displacement, u is the initial velocity, t is the time taken and a is the acceleration.

s = 6 m, t = 0.5 seconds, a = acceleration due to gravity value = -9.8

 Substituting

 Initial speed of the ball = 14.45 m/s

 b) We have equation of motion , where v is the final velocity

   s = 6 m, u = 14.45 m/s, a = -9.8

    Substituting

  So at height 6 m speed of ball = 9.55 m/s

c) We have equation of motion , where v is the final velocity

   u = 14.45 m/s, v =0 , a = -9.8

   Substituting

  Maximum height reached = 10.65 m

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

scientific laws are the result of testing theories and proving them to be facts.