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3 years ago

The sun rose at 6:54 this morning.is this an observation or inference?

Physics

2 answers:

Levart [38]3 years ago

8 0

Answer:

observation

Explanation:

Through an observation information is acquired. The acquiring of information must be through the five senses directly or indirectly. When a person takes an observation using eyes it is a form direct observation. When a person takes an observation using scientific instruments it is a form indirect observation.

Inference is the deduction of observations taken.

Here, the sun rose at 6:54 this morning is an observation i.e., a person saw the sun rise at 6:54. It has not been deduced that the sun rose at 6:54.

jeka57 [31]3 years ago

4 0

Observation: You saw/ observed something and you are stating that.

Inference: You are predicting something to be true. If so and so, then this will occur.

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Read 2 more answers

If the coefficient of friction is 0.3900 and the cylinder has a radius of 2.700 m, what is the minimum angular speed of the cyli

Aleks04 [339]

Answer:

w=3.05 rad/s or 29.88rpm

Explanation:

k = coefficient of friction = 0.3900

R = radius of the cylinder = 2.7m

V = linear speed of rotation of the cylinder

w = angular speed = V/R or to rewrite V = w*R

N = normal force to cylinder

N= $=\frac{m(V)^{2}}{R}=m*(w)^2*R$

$Friction force\\Ff = k*N\\Ff= k*m*w^2*R$

$Gravitational force \\Fg = m*g$

These must be balanced (the net force on the people will be 0) so set them equal to each other.

$Fg = Ff$

$m*g = k*m*w^2*R$

$g=k*w^{2}*R$

$w^2 =\frac{g}{k*R}$

$w=\sqrt{\frac{g}{k*R}} \\w =\sqrt{\frac{9.8\frac{m}{s^{2}}}{0.3900*2.7m}}\\ w=\sqrt{9.306}=3.05 \frac{rad}{s}$

There are 2*pi radians in 1 revolution so:

$RPM=\frac{w}{2\pi }*60\\RPM=\frac{3.05\frac{rad}{s}}{2\pi}*60\\RPM= 0.498*60\\RPM=29.88$

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4 years ago

A 20000 kg railroad car is rolling at 1.00 m/s when a 1000 kg load of gravel is suddenly dropped in. part a what is the car's sp

Talja [164]

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3 years ago