What is the atomic number of potassium?

A triangle has angles measuring 10°, 40°, and 130° with side lengths of 23 cm, 84 cm, and 100 cm. Classify this triangle by its

Maurinko [17]

For the lengths of its sides
As a scalene triangle (from the Greek σκαληνός "unequal"), if all its sides have different lengths (in a scalene triangle there are no two angles having the same measure)
For its angles
obtuse triangle: if one of its interior angles is obtuse (greater than 90 °); the other two are acute (less than 90 °).

5 0

3 years ago

At which temperature does the motion of atoms and molecules stop?

Scorpion4ik [409]

Answer:

0 Kelvin

Explanation:

Atoms in absolute temperature get approximatelly motionless since 0 Kelvin is -273 degrees Celcius. The kinetic energy of atoms/particles in matter has the possible lowest value ( almost zero), so that there is nothing colder than 0 Kelvin.

4 0

3 years ago

A rock is tossed straight up from the ground with a speed of 21 m/s . When it returns, it falls into a hole 10 m deep.a.) What i

Arte-miy333 [17]

(a) 25.2 m/s

Let's take the initial vertical position of the rock as "zero" (reference height).

According to the law of conservation of energy, the speed of the rock as it reaches again the position "zero" after being thrown upwards is equal to the initial speed of the rock, 21 m/s (in fact, if there is no air resistance, no energy can be lost during the motion; and since the kinetic energy depends only on the speed of the rock:

$K=\frac{1}{2}mv^2$

and the gravitational potential energy of the rock has not changed, since the rock has returned into its initial position, it means that the speed of the rock should be the same)

This means that we can only analyze the final part of the motion, the one in which the rock falls into the 10 m hole. Since it is a free fall motion, we can find the final speed by using

$v^2 = u^2 + 2gd$