Answer:
The time taken by the brick to hit the ground, t = 0.84 s
Explanation:
Given that,
A brick falls from a height, h = 3.42 m
The initial velocity of the brick is zero.
Since the brick is under free-falling. The time equation of a free-falling body when the displacement is given is
t = 
where,
h - height from surface in meters
g - acceleration due to gravity
on substituting the values in the above equation,
t = 
= 0.84 s
Hence, time taken by the brick to hit the ground is t = 0.84 s
Answer:
ω₂=1.20
Explanation:
Given that
mass of the turn table ,M= 15 kg
mass of the ice ,m= 9 kg
radius ,r= 25 cm
Initial angular speed ,ω₁ = 0.75 rad/s
Initial mass moment of inertia



Final mass moment of inertia



Lets take final speed of the turn table after ice evaporated =ω₂ rad/s
Now by conservation angular momentum
I₁ ω₁ =ω₂ I₂

ω₂=1.20
Dominoes does because when you hit one, it knocks over the next one, and so on, so forth. The same type of pattern happens in a wave.
The change in Potential energy of the cat is 176.4 J.
<h3 /><h3>Potential Energy:</h3>
This is the energy due to the position of a body. The S.I unit is Joules (J)
The formula for change in potential energy.
<h3 /><h3>Formula:</h3>
- ΔP.E = mg(H-h).............. Equation 1
<h3>Where:</h3>
- ΔP.E = Change in potential energy
- m = mass of the cat
- g = acceleration due to gravity
- H = First height
- h = second height.
From the question,
<h3>Given:</h3>
- m = 15 kg
- H = 2.5 m
- h = 1.3 m
- g = 9.8 m/s²
Substitute these values into equation 1
- ΔP.E = 15×9.8(2.5-1.3)
- ΔP.E = 15×9.8×1.2
- ΔP.E = 176.4 J.
Hence, The change in Potential energy of the cat is 176.4 J
Learn more about Potential energy here: brainly.com/question/1242059
C- 10ft. Hope this helped. Have a great day! :D