Answer:
4. 10.0 m/s²
Explanation:
I) if initial velocity is 'v₀', the final velocity is 'v', the accelaration is 'a', the distance is 'L' and elapsed time if 't', then:


II) using these two equations after substitution v₀=0; v=30 and L=45:


Answer:
<em>When a balloon deflates air moves out of the balloon </em><em>because the pressure inside the balloon is higher than the pressure outside the balloon.</em>
Explanation:
An inflated balloon has a high pressure region on its inside. Gases always move from a region of high pressure to a region of low pressure. When a balloon is inflated its membrane stretches making it even more porous.
The gas molecules inside the balloon easily diffuse out through this membrane. The diffusion rate may differ depending on the type of gas filled inside the balloon and the material of the balloon. For example helium balloon deflates faster than common air balloon.
This is because helium is a light element and can escape easier than gases like nitrogen and oxygen through the porous membrane of the balloon.
(a) The ball’s maximum speed over the net is v(max) = √2gh.
(b) The maximum speed of the horizontally moving ball clearing the net is about 27 m/s.
(c) Speed of the ball is independent of its mass.
<h3>
Time of motion of the ball</h3>
The time of motion of the ball is calculated as follows;
h = vt + ¹/₂gt²
1 = 0 + ¹/₂(9.8)t²
1 = 4.9t²
t² = 1/4.9
t² = 0.204
t = 0.452 s
<h3>Horizontal speed of the ball</h3>
The horizontal speed of the ball is calculated as follows;
X = vt
v = X/t
v = (12 m)/(0.452)
v = 26.6 m/s ≈ 27 m/s (proved)
<h3>Conservation of energy</h3>
P.E = K.E
mgh = ¹/₂mv²
gh = ¹/₂v²
2gh = v²
√2gh = v(max)
Speed of the ball is independent of its mass.
Learn more about horizontal velocity here: brainly.com/question/24681896
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Explanation:
a. KE at bottom = PE at top
½ mv² = mgh
v = √(2gh)
v = √(2 × 9.8 m/s² × 20.0 m)
v = 19.8 m/s
b. Work by friction = PE at top
mgμ d = mgh
d = h / μ
d = 20.0 m / 0.210
d = 95.2 m