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3 years ago

Secondary evidence is the basis for drawing scientific conclusions is this true ir false

2 answers:

7 0

The statement: "secondary evidence is the basis for drawing scientific conclusions" is definitely false. Secondary evidence is the body of information obtained to prove the existence of unknown or missing primary evidence. In drawing scientific conclusions, primary evidence is needed.

wel3 years ago

4 0

Answer:

False

Explanation:

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A heavy stone of mass m is hung from the ceiling by a thin 8.25-g wire that is 65.0 cm long. When you gently pluck the upper end

Dominik [7]

Answer:

wavelength = 0.8989 m

Explanation:

Given data:

weight of wire is 8.25 g

length of wire is 65 cm

speed of sound in room is 344 m/s

time of returning of pulse is 7.84 ms

There are three time period

Time period $= \frac{7.84\times 10^{-3}}{3} = 2.6133\times 10^{-3} s$

$frequency = \frac{1}{T}$

$=\frac{ 1}{2.6133\times 10^{-3})} = 382.6579 Hz$

velocity = wavelength × frequency

wavelength $= \frac{velocity}{frequency}$

$= \frac{344}{382.6579}$

wavelength = 0.8989 m

6 0

3 years ago

A current of 1.75 A flows through a 55.4 Ω resistor for 9.5 min. How much heat was generated by the resistor? Answer in units of

kirill115 [55]

Answer:

$9.67\times 10^4 J$

Explanation:

We are given that

Current=I=1.75 A

Resistance =R=55.4 ohm

Time=t=9.5 min= $9.5\times 60=570 s$

1 min=60 s

We have to find the heat generated by the resistor.

We know that

Heat=E= $I^2Rt$

Using the formula

Heat, $E=(1.75)^2\times 55.4\times 570=9.67\times 10^{4} J$

Hence, the heat generated by the resistor = $9.67\times 10^4 J$

6 0

3 years ago

A 96.0 kg hoop rolls along a horizontal floor so that its center of mass has a speed of 0.240 m/s. How much work must be done on

Ede4ka [16]

Answer:

The work done by the hoop is equal to 5.529 Joules.

Explanation:

Given that,

Mass of the hoop, m = 96 kg

The speed of the center of mass, v = 0.24 m/s

To find,

The work done by the hoop.

Solution,

The initial energy of the hoop is given by the sum of linear kinetic energy and the rotational kinetic energy. So,

$K_i=\dfrac{1}{2}mv^2+\dfrac{1}{2}I\omega^2$

I is the moment of inertia, $I=mr^2$

Since, $\omega=\dfrac{v}{r}$

$K_i=mv^2$

$K_i=96\times (0.24)^2=5.529\ J$

Finally it stops, so the final energy of the hoop will be, $K_f=0$

The work done by the hoop is equal to the change in kinetic energy as :

$W=K_f-K_i$

W = -5.529 Joules

So, the work done by the hoop is equal to 5.529 Joules. Therefore, this is the required solution.

4 0

3 years ago

How much momentum does a 300 kg truck have when traveling 4 m/s

spin [16.1K]

p=mv

p=300kg*4m/s

p=1200kg m/s

idk the direction

4 0

3 years ago

Find equation tangent to a circle at given point

vlabodo [156]

the equation of the tangent line must be passed on a point A (a,b) and perpendicular to the radius of the circle. 
I will take an example for a clear explanation:
let x² + y² = 4 is the equation of the circle, its center is C(0,0). And we assume that the tangent line passes to the point A(2.3).

since the tangent passes to the A(2,3), the line must be perpendicular to the radius of the circle.

Let's find the equation of the line parallel to the radius.

The line passes to the A(2,3) and C (0,0). y= ax+b is the standard form of the equation. AC(-2, -3) is a vector parallel to CM(x, y).

det(AC, CM)= -2y +3x =0, is the equation of the line // to the radius.

let's find the equation of the line perpendicular to this previous line.

let M a point which lies on the line. so MA.AC=0 (scalar product),

it is (2-x, 3-y) . (-2, -3)= -4+4x + -9+3y=4x +3y -13=0 is the equation of tangent

7 0

4 years ago