Answer:
4.24m/s
Explanation:
Potential energy at the top= kinetic energy at the button
But kinetic energy= sum of linear and rotational kinetic energy of the hoop
PE= mgh
KE= 1/2 mv^2
RE= 1/2 I ω^2
Where
m= mass of the hoop
v= linear velocity
g= acceleration due to gravity
h= height
I= moment of inertia
ω= angular velocity of the hoop.
But
I = m r^2 for hoop and ω = v/r
giving
m g h = 1/2 m v^2 + 1/2 (m r^2) (v^2/r^2) = 1/2 m v^2 + 1/2 m v^2 = m v^2
and m's cancel
g h = v^2
Hence
v= √gh
v= √10×1.8
v= 4.24m/s
Answer:
The actual elevation angle is 12.87 degrees
Explanation:
In the attachment you can clearly see the situation. The angle of elevation as seen for the scuba diver is shown in magenta, we conclude that
.
Using Snell's Law we can write:

,
Let's approximate the index of refraction of the air (medium 1 in the picture) to 1.
We thus have:

. Calling
the actual angle of elevation, we get from the picture that
Answer:
(a) has the highest frequency
Explanation:
E = hf...where E(is the energy of a photon);h(is the planck's constant) and f is the frequency of the photon
Whereby this formula shows us that energy of a photon is directly proportional to its frequency
So hence if the energy is high then the frequency of the photon is also high
Answer:42.43m/s
Explanation:According to vf=vi+at, we can calculate it since v0 equals to 0. vf=0+9.8m/s^2*4.33s= 42.434m/s
Answer:
Perm lasts longer
Explanation:
Cuz a chemical relaxer only lasts a few weeks and a perm lasts a few months hope this helps