Why are the orbits of planets only nearly circular and not perfectly circular?

What subatomic particle determines the identity of an element

FinnZ [79.3K]

Answer:

Proton

Explanation:

Proton is a subatomic particle and determines the identity of an element. each element is identified by its atomic number. In an element, the number of protons in the nuclei of the atoms of the element is same as the atomic number of that element and this number is different for each element. for example, Boron has 5 protons in its nuclei, hence the atomic number of the element is 5.

3 0

3 years ago

You are pulling a child in a wagon. The rope handle is inclined upward at a 60∘ angle. The tension in the handle is 20 N.

dem82 [27]

Angle (θ) = 60°
Force (F) = 20 N
Distance (s) = 200 m
Therefore, work done
= Fs Cos θ
= (20 × 200 × Cos 60°) J
= (20 × 200 × 1/2) J
= (20 × 100) J
= 2000 J

Answer:

2000 J

Hope you could get an idea from here.

Doubt clarification - use comment section.

6 0

2 years ago

Read 2 more answers

All of the following show friction as a useful force, except

Troyanec [42]

having to push a rough and heavy box across the floor to move it

Explanation:

Friction is not a useful force because we have to exert even more force to push a body that is rough and heavy across the floor to move it.

Frictional force is a force that opposes the motion of a body.
It costs more and uses more energy to push a rough and heavy box on surface because of friction.
This wastes energy in systems that deals with pushing.

Friction is useful in that:

the heat energy produced when two surfaces rub together is very useful.
the friction between your feet and the floor keeping you from slipping and makes walking possible.
the tread on tires helping the moving vehicle slow down and stop when necessary.

learn more:

Friction brainly.com/question/7174363

#learnwithBrainly

3 0

3 years ago

An irregularly shaped rock is placed in 50 mL of water. The new reading in the container is now 74.2 mL. If the mass of the rock

cricket20 [7]

Taking into account the definition of density, the density of the rock is 3.6583 g/mL.

<h3>Definition of density</h3>

Density is defined as the property that matter has to compress into a given space.

In other words, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance.

The expression for the calculation of density is:

density= mass÷ volume

From this expression it can be deduced that density is inversely proportional to volume: the smaller the volume occupied by a given mass, the higher the density.

<h3>Density of the rock</h3>

In this case, you know that:

Mass= 88.53 g
Volume of the rock= Volume after place the rock in the water - Volume of water= 74.2 mL - 50 mL= 24.2 mL

Replacing in the definition of density:

density of rock= 88.53 g÷ 24.2 mL

Solving:

density of rock= 3.6583 g/mL

In summary, the density of the rock is 3.6583 g/mL.

Learn more about density:

brainly.com/question/952755

brainly.com/question/1462554

#SPJ1

8 0

2 years ago

3. A rocket is launched at an angle of 53 degrees above the 1 point

irina1246 [14]

Answer:

24,000 m

Explanation:

First find the rocket's final position and velocity during the first phase in the y direction.

Given:

v₀ = 75 sin 53° m/s

t = 25 s

a = 25 sin 53° m/s²

Find: Δy and v

Δy = v₀ t + ½ at²

Δy = (75 sin 53° m/s) (25 s) + ½ (25 sin 53° m/s²) (25 s)²

Δy = 7736.8 m

v = at + v₀

v = (25 sin 53° m/s²) (25 s) + (75 sin 53° m/s)

v = 559.0 m/s

Next, find the final position of the rocket during the second phase (as a projectile).

Given:

v₀ = 559.0 m/s

v = 0 m/s

a = -9.8 m/s²

Find: Δy

v² = v₀² + 2aΔy

(0 m/s)² = (559.0 m/s)² + 2 (-9.8 m/s²) Δy

Δy = 15945.5 m

The total displacement is:

7736.8 m + 15945.5 m

23682.2 m

Rounded to two significant figures, the maximum altitude reached is 24,000 m.

3 0

3 years ago