Question

A ball is thrown up ward from the ground . It is at aheight of 100m in upward and downward journeys at times t1 and t2 respectively and g = 10 mls^s then t1*t2 is equal to ?

Answer 1

Explanation:

supporting statement:

A ball is thrown up ward from the ground . It is at a height of 100m in upward and downward journeys at times t1 and t2 respectively

in first case,

g=(-10) m/s^2

u=0

h=100m=s

according to Newton's second law of motion...........

s=1/2 g t1^2

100=1/2 (-10) t1^2

100= -5 t1^2

t1^2 = 95

t1= 9.74

in case 2:

g=(+10) m/s^2

u=0

h=100m=s

according to Newton's second law of motion...........

s=1/2 g t2^2

100=1/2 (+10) t2^2

t2^2=105

t2=10.24

9.74 × 10.24

= 99.73 ~ 100

hope it helps

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