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3 years ago

Which statement describes a scientific theory?

Physics

1 answer:

PSYCHO15rus [73]3 years ago

4 0

Answer:

A theory changes based on new observations and testing.

Explanation:

A scientific theory is a product of multiple trials and repeated experiments. It usually follows after carefully conducting and testing the validity of the hypothesis.

A scientific theory provides an explanation into how something behaves.

A law just states a finding will not explain it.

Most theories are tenable and can be improved upon when new observations and testing are carried out.

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What properties of sound determine the volume of sound? Is this affected by the motion of the sound source?

Alik [6]

The amplitude determines the volume of the sound. This isn't affected by the motion of the sound source.
Hope this helps

6 0

3 years ago

You have a horizontal grindstone (a disk) that is 86 kg, has a 0.33 m radius, is turning at 92 rpm (in the positive direction),

Rudiy27

Answer:

a) α = 0.338 rad / s² b) θ = 21.9 rev

Explanation:

a) To solve this exercise we will use Newton's second law for rotational movement, that is, torque

τ = I α

fr r = I α

Now we write the translational Newton equation in the radial direction

N- F = 0

N = F

The friction force equation is

fr = μ N

fr = μ F

The moment of inertia of a saying is

I = ½ m r²

Let's replace in the torque equation

(μ F) r = (½ m r²) α

α = 2 μ F / (m r)

α = 2 0.2 24 / (86 0.33)

α = 0.338 rad / s²

b) let's use the relationship of rotational kinematics

w² = w₀² - 2 α θ

0 = w₀² - 2 α θ

θ = w₀² / 2 α

Let's reduce the angular velocity

w₀ = 92 rpm (2π rad / 1 rev) (1 min / 60s) = 9.634 rad / s

θ = 9.634 2 / (2 0.338)

θ = 137.3 rad

Let's reduce radians to revolutions

θ = 137.3 rad (1 rev / 2π rad)

θ = 21.9 rev

7 0

3 years ago

A car travels 200m in 30 s and 400m in the next 90s. Whats the average speed?

VLD [36.1K]

Answer:

300m per minute or 5m per second

6 0

3 years ago

(d) Suppose you use a spring to launch a payload horizontally from the asteroid so that the payload ends up far from the asteroi

nydimaria [60]

Answer:

ks= 133.2 N/m

Explanation:

Assuming that we can neglect the gravitational potential energy of the mass, and that no other forces acting on the payload, total mechanical energy must be conserved.
This energy, at any time, is part elastic potential energy (stored in the spring) and part kinetic energy.
When the spring is initially compressed, the payload is at rest, so all energy is elastic potential.
Once the spring has returned to its natural state, all this elastic potential energy must have been turned into kinetic energy.
If the payload is launched horizontally, and no gravity is present,this means that its final speed will be horizontal only also, according to Newton's First Law.
So, we can write the following equation:

$\Delta U + \Delta K = 0 (1)$

where ΔU = -1/2*k*(Δx)² (2)
and ΔK = 1/2*m*v² (3)
Replacing in (2) and (3) by the givens, and simplifying, we can find the stiffness ks as follows:

$k_{s} =\frac{m*v^{2}}{\Delta x^{2}} = \frac{29 kg*(3m/s)^{2}}{(1.4m)^{2}} = 133.2 N/M (4)$

5 0

2 years ago

Which is directly proportional to your weight on a planet's surface?

Oduvanchick [21]

D. Your mass and the mass of the planet

5 0

3 years ago

Read 2 more answers