Twenty students were surveyed to find out how many hours of tv they watch during a school week
1 answer:
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Answer:
he sphere that uses less time is sphere A
Explanation:
Let's start with ball A, for this let's use the kinematics relations
v² = v₀² - 2g (y-y₀)
indicate that the sphere is released therefore its initial velocity is zero and when it reaches the floor its height is zero y = 0
v² = 0 - 2 g (0- y₀)
v =
v =
v = 4.427 √H
Now let's work the sphere B, in this case it rolls down a ramp, let's use the conservation of energy
starting point. At the highest point, before you start to move
Em₀ = U = m g y
final point. At the bottom of the ramp
Em_f = K = ½ m v² + ½ I w²
notice that we include the kinetic energy of translation and rotation
energy is conserved
Em₀ = Em_f
mg H = ½ m v² + ½ I w²
angular and linear velocity are related
v = w r
w = v / r
the momentorot of inertia indicates that it is worth
I = m r²
we substitute
m g H = ½ m v² + ½ ( m r²) (
)²
gH = v² +
v² =
v²
v =
v =
v=3.742 √H
Taking the final speeds of the sphere, let's analyze the distance traveled, sphere A falls into the air, so the distance traveled is H. The ball B rolls in a plane, so the distance (L) traveled can be found with trigonometry
sin θ = H / L
L = H /sin θ
we can see that L> H
In summary, ball A arrives with more speed and travels a shorter distance, therefore it must use a shorter time
Consequently the sphere that uses less time is sphere A
Complete question is;
An experiment is carried out to measure the extension of a rubber band for different loads.
The results are shown in the image attached.
What figure is missing from the table?
Answer:
17.3 cm
Explanation:
The image attached showed values for load, extension and initial length.
Now, the first length there is 15.2 cm and as such it's corresponding extension is 0 because it has no preceding measured length.
The second measured length is 16.2 cm. Since it's initial measured length is 15.2 cm, then the extension has a formula; final length - initial length.
This gives: 16.2 - 15.2 = 1 cm
This corresponds to what is given in the table.
For the next measured length, it is blank but we are given the extension to be 2.1 cm. Now, since the initial measured length is 15.2 cm.
Thus;
2.1 cm = Final length - 15.2 cm
Final length = 15.2 + 2.1
Final length = 17.3 cm
