Which scientist discovered the two radioactive elements radium and polonium?

Groups of students are making measurements of small cars rolling across a table. the class has measuring tapes with markings in

TiliK225 [7]

To find the accurate measurement of small cars, the teacher asks students to make all the measurements in centimeters.

Centimeters Measurements:

A centimeter is a metric unit of measurement used for measuring the length of an object, It is written as cm
Centimeter is one hundredth of a meter, 1 meter is 0.01 cm.

Inches measurements:

An inch can be defined as a unit of length in the customary system of measurement. Length in inches is either represented by in or ''.
1 meter is equal to 39.37 inches

here, the cars are small objects.

The number of centimeters is always bigger,

because a centimeter unit is smaller than an inch unit, and it takes more of them when we are measuring.

Hence,

To find the accurate measurement of small cars, the teacher asks students to make all the measurements in centimeters.

Learn more about accurate measurement here:

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4 0

2 years ago

Check all that apply. The magnetic force on the current-carrying wire is strongest when the current is parallel to the magnetic

dedylja [7]

Answer:

The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field.

The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current.

The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines.

Explanation:

The magnitude of the magnetic force exerted on a current-carrying wire due to a magnetic field is given by

$F=ILB sin \theta$ (1)

where I is the current, L the length of the wire, B the strength of the magnetic field, $\theta$ the angle between the direction of the field and the direction of the current.

Also, B, I and F in the formula are all perpendicular to each other. (2)

According to eq.(1), we see that the statement:

"The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines."

is correct, because when the current is perpendicular to the magnetic field, $\theta=90^{\circ}, sin \theta = 1$ and the force is maximum.

Moreover, according to (2), we also see that the statements

"The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field. "

"The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current. "

because F (the force) is perpendicular to both the magnetic field and the current.

5 0

3 years ago

How would a scientist go about determining if an unknown substance is an element, compound, solution, or heterogeneous mixture?

stepan [7]

each of more than one hundred substances that cannot be chemically inter converted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e., the number of protons in the nuclei of its atoms. thats part of one

5 0

3 years ago

A paper clip is made of wire 0.5 mm in diameter. If the original material from which the wire is made is a rod 25 mm in diameter

gizmo_the_mogwai [7]

Answer:

longitudinal engineering strain = 624.16

true strain is 6.44

Explanation:

given data

diameter d1 = 0.5 mm

diameter d2 = 25 mm

to find out

longitudinal engineering and true strains

solution

we know both the volume is same

so

volume 1 = volume 2

A×L(1) = A×L(2)

( π/4 × d1² )×L(1) = ( π/4 × d2² )×L(2)

( π/4 × 0.5² )×L(1) = ( π/4 × 25² )×L(2)

0.1963 ×L(1) = 122.71 ×L(2)

L(1) / L(2) = 122.71 / 0.1963 = 625.16

and we know longitudinal engineering strain is

longitudinal engineering strain = L(1) / L(2) - 1

longitudinal engineering strain = 625.16 - 1

longitudinal engineering strain = 624.16

and

true strain is

true strain = ln ( L(1) / L(2))

true strain = ln ( 625.16)

true strain is 6.44

3 0

4 years ago

A person throws a ball and angle of 30° a velocity of 40 m/s how fast is the ball traveling up?

Zanzabum

Answer:

20 m/s

Explanation:

The vertical component of the velocity of the ball is equal to the length of the perpendicular of a triangle such that it makes an angle of 30 degrees from the base and the length of the hypotenuse is 40 m/s. Sin(∅)*hypotenuse is the length of the perpendicular.

Vertical component of velocity is given by 40Sin(30°)=20

8 0

3 years ago