A. is a neutral substance a pH of 7 describes something of neutral pH where anything less than 7 is an acid and higher is a base
GPE= 70.56 J -------------------> GPE= mgh-------------> X= height
70.56 = 6(kg) * 9.8(m/s/s) * X
70.56 = 58.8X
70.56/58.8= 58.8X/58.8
X= 1.2
The height is 1.2 feet or meters (whatever unit you are using in this problem)
Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height

To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height



So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point



Solving the quadratic equation



So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:


Since the projectile is going down the velocity at the instant it reaches the ground is:

Answer:
They will not meet
h-hX=1.2*g*t²
hX=v0*t-(1/2*g*t²)
Explanation:
fall h=1/2*g*t²
elevation time if v0=20 m/s te=v0/g=20 m/s /9.81 m/s²=2.0387s
hmax=v0²/(2*g)=(400 m²/s²)/19.62 m/s²2=20.387 m
free fall
t=2.0387s yields hX=1/2*g*t²=20.387 m
h-hX=200m - 20.387 m=179,613 m.
so, the second body has not enough initianoal speed to reach a meeting point