can ya pls answer dis rq!

Answer:

Elements in the same group have the same number of valence electrons.

When moving right across a period, the valence electrons of the main group elements increase by one.

When moving down a group, the valence electrons of the main group elements increase by one.

Elements in the same period have the same number of valence electrons.

Elements in the same period of the periodic table have valence electrons in the same energy levels.

When elements are in the same period on the periodic table, it means that they have the same number of shells.

The energy level of valence electrons in a atom depends on how far it is from the nucleus. This means that:

For instance, Boron, Carbon and Nitrogen will have valence electrons in the same energy levels.

In conclusion, elements in the same period will have valence electrons in the same energy levels.

Find out more at https://brainly.com/question/21367069.

Explanation:

string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.

hence the we apply force on the roller and the string gets tight.

Answer:

1) The kinetic energy of the object after it drops for 2.0 seconds is approximately 384.9 Joules

2) The potential energy of the object after it drops for 2.0 seconds is approximately 204 J

Explanation:

1) The given mass of the object, m = 2.0 kg

The height from which the object is dropped, h = 30 m

The kinetic energy of the object after it drops for 2.0 seconds = Required

Kinetic energy, K.E. = (1/2)·m·v²

Where;

v = The velocity of the object

The kinematic equation for finding the velocity of the object is presented as follows;

v = u + g·t

Where;

u = The initial velocity of the object = 0

g = The acceleration due to gravity of the object ≈ 9.81 m/s²

t = The time of motion of the object = 2.0 seconds

∴ The velocity after 2 seconds, v ≈ 0 + 9.81 m/s² × 2 s = 19.62 m/s

The kinetic energy, K.E. after 2 seconds as the object drops is given as follows;

[tex]K.E._{(after \ two \ seconds)}[/tex] = (1/2) × 2.0 kg × (19.62 m/s)² = 384.9444 J ≈ 384.9 J

2) The total energy, M.E. of the object at the top, h = 30 m, u = 0, is given as follows;

The total mechanical energy, M.E. = P.E. + K.E.

M.E. = m·g·h + (1/2)·m·u²

∴ M.E. = 2.0 kg × 9.81 m/s² × 30 m + 0 = 588.6 J

M.E. = 588.6 J

Given that the total mechanical energy, M.E., is constant, we have;

At 2.0 seconds, M.E. = 588.6 J , K.E. ≈ 384.9 J, P.E. = M.E. - K.E.

∴ P.E. = 588.9 J - 384.9 J ≈ 204 J

The potential energy after it drops 2.0 seconds, P.E. ≈ 204 J

Answer:

Parallel

Explanation:

The work done is defined as the force applied on an object and the displacement in the position of the object in the direction of force.

W = F s cos A

where, F is the force, s is the displacement and A is the angle between force and displacement.

When the angle between the force and the displacement is 90 degree, the work done is zero.

To get the maximum work the angle between the force and the displacement is 0 degree.

So, to get the work done by the force the angle between the force and displacement is 0 degree that means the force and displacement is parallel to each other.

(a) The recoil or backward velocity of the gun is 8 m/s.

(b) The bullet cannot penetrate the plank of the wood completely.

The given parameters include;

(a) The backward or recoil velocity of the gun is calculated by applying the principle of conservation of linear momentum.

m₁u₁  + m₂u₂ = 0

m₂u₂ = -m₁u₁

[tex]u_2 = -\frac{m_1u_1}{m_2} \\\\u_2 = - \frac{0.1 \times 400}{5} \\\\u_2 = -8 \ m/s[/tex]

Thus, the recoil or backward velocity of the gun is 8 m/s.

(b) determine if the bullet can penetrate the plank of the wood completely

the acceleration of the bullet is calculated as;

v² = u₁² + 2as

2as = v² - u²

[tex]a = \frac{v^2 -u_1^2}{2s} \\\\a = \frac{(266.67)^2 -(400)^2}{2\times 0.04} = -1.111 \times 10^6 \ m/s^2[/tex]

Finally, determine the distance traveled by the bullet when it comes to a complete stop, that is the final velocity = 0

[tex]v_f^2 = v^2 + 2ad\\\\2ad = v_f^2 - v^2\\\\d = \frac{v_f^2 - v^2}{2a} \\\\d = \frac{(0) - (266.67)^2}{2(-1.111\times 10^6)} \\\\d = 0.032 \ m[/tex]

d = 3.2 cm

The total distance traveled by the bullet inside the plank = 4 cm + 3.2 cm = 7.2 cm

Therefore, the bullet cannot penetrate the plank completely.

To learn more about linear momentum visit: https://brainly.com/question/15869303

Answer:

Explanation:

We first need to convert the 40 km/h to m/s. Going by the fact that 40 has only 1 significant figure in it, 40 km/h = 10 m/s. The rest of the values are in their proper labels. We will use the equation:

[tex]v^2=v_0^2+2a[/tex]Δx where the final velocity is 0 because the car is coming to a stop at the end; the initial velocity is 10 m/s, the acceleration (or, rather, deceleration) is -.5 m/s/s, and our unknown which is displacement. Filling in:

[tex]0=(10)^2+2(-.5)[/tex]Δx and solving for Δx:

Δx = [tex]\frac{-100}{2(-.5)}[/tex] which ends up being simply that

Δx = 100 m

Answer:

hi

Explanation:

pls mark as a BRAINLIST

The average acceleration of the bike is 2.2 m/s²

Acceleration, rate at which velocity changes with time, in terms of both speed and direction.

A point or an object moving in a straight line is accelerated if it speeds up or slows down.

According to the question,

Given, initial velocity, u=3.0m/s and final velocity v=8.5 m/s

Time = 2.5 seconds

If a be the acceleration.

a = [tex]\frac{v-u}{t}[/tex]

a = [tex]\frac{8.5 - 3.0}{2.5s}[/tex]

⟹ a=2.2 m/s²

So, The average acceleration of the bike is 2.2 m/s²

Learn more about average acceleration here:

https://brainly.com/question/2303856

#SPJ2

Answer:

A stone is more dense than water and the air in draft of the boat is less dense than water.

The magnitude (size or numerical value) and the direction.

Hope this helps!!! :)

Answer:

The final translational seed at the bottom of the ramp is approximately 4.84 m/s

Explanation:

The given parameters are;

The radius of the sphere, R = 2.50 cm

The mass of the sphere, m = 4.75 kg

The translational speed at the top of the inclined plane, v = 3.00 m/s

The length of the inclined plane, l = 2.75 m

The angle at which the plane is tilted, θ = 22.0°

We have;

[tex]K_i[/tex] + [tex]U_i[/tex] = [tex]K_f[/tex] + [tex]U_f[/tex]

K = (1/2)×m×v²×(1 + I/(m·r²))

I = (2/5)·m·r²

K =  (1/2)×m×v²×(1 + 2/5) = 7/10 × m×v²

U = m·g·h

h = l×sin(θ)

h = 2.75×sin(22.0°)

∴ 7/10×4.75×3.00² + 4.75×9.81×2.75×sin(22.0°) = 7/10 × 4.75×[tex]v_f[/tex]² + 0

7/10×4.75×3.00² + 4.75×9.81×2.75×sin(22.0°) ≈ 77.93

∴ 77.93 ≈ 7/10 × 4.75×[tex]v_f[/tex]²

[tex]v_f[/tex]² = 77.93/(7/10 × 4.75)

[tex]v_f[/tex] ≈ √(77.93/(7/10 × 4.75)) ≈ 4.84

The final translational seed at the bottom of the ramp, [tex]v_f[/tex] ≈ 4.84 m/s.

Answer:

cần cung cấp 70 độ vì nước sôi ở 100°C

Explanation:

Answer:

But negative acceleration means that the rate of change of velocity is negative or velocity decreases. Example: (1) When we apply brakes in a moving car, then negative acceleration acts on it and the car stops. (2) When we throw a ball upwards, then also negative acceleration acts on it.

Explanation:

If it helps you mark me as a brainleast

MATHEMATICALLY A NEGATIVE ACCELERATION MEANS YOU WILL SUBTRACT FROM THE CURRENT VALUE OF THE VELOCITY.

Answer:

d. was formed by the collision of the Earth with a Mars-sized protoplanet.

According to the The giant-impact hypothesis the Moon was formed from the debris of a collision between the Earth and a Mars-sized protoplanet.

Answer:

when it comes to machines being Rusty oil is like the root loosener

Answer:

The heat gives atoms/ particles in balloon more kinetic energy so they move further apart, increasing size and eventually popping balloon

^ very simple explanation

Explanation:

Option ( iv ) is the correct answer.

A vector quantity the physical quantity that has both direction as well as magnitude.

Answer:

Pascal is a derived unit because it cannot be expressed in any physics terms, but it is an expression of fundamental quantities.

Explanation:

[tex]{ \sf{Pasacal \: ( Pa) = \frac{newtons}{metres {}^{2} } }} \\ \\ { \sf{Pasacal \: (Pa) = \frac{kg \times {ms}^{ - 2} }{ {m}^{2} } }}[/tex]

Doppler frequency, the other car hear before they pass each other is 668.68 Hz.

Frequency is the number of occurrences of a repeating event per unit of time.

The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source.

According to the Doppler Effect, the frequency observed is

  [tex]fo=fs\frac{v+v_{o} }{v-v_{s} }[/tex]

[tex]f_{o}=595\frac{343+20 }{343-20 }\\f_{o} = 668.68 Hz[/tex]

To know more about Doppler Effect here

https://brainly.com/question/15318474

#SPJ2

[tex]\boxed{\sf W=Fscos\Theta}[/tex]

[tex]\\ \sf\longmapsto W=150(50)cos 60[/tex]

[tex]\\ \sf\longmapsto W=7500\times \dfrac{1}{2}[/tex]

[tex]\\ \sf\longmapsto W=3750J[/tex]

Answer:

Uniform motion is a type of motion that is characterized as the motion of an object wherein the object moves in a straight line and its velocity remains unchanged along that line, regardless of the duration of time, as it occupies equal distances at equal time interval and Non-uniform motion is described as the motion of an object wherein the object moves at different speeds and does not cover the same distance at equal time intervals, regardless of the duration of the time interval.

Answer:

hope it's help you

Explanation:

In Uniform motion, the movement of a body is along the straight line with constant speed. In non uniform motion, the movement of a body is along the straight line with variable speed. In uniform motion, the body covers equal distance in an equal interval of time.

Answer:

No, it's not there.

Explanation:

For a machine to be 100% efficient, it has to be with an output which is equal to its input. But machines have an out put less than an input, hence efficiency below 100%.

Answer:

A. Contains DNA

C. Contains ribosomes

F. Lacks a nucleus

Explanation:

Answer:

3012.012m

Explanation:

s=it +1/2(10.8)(16.7)^2

Answer:

A

The upthrust on a floating body is in upwards direction and is equal to the weight of the liquid displaced

B

The upthrust is directly proportional to the density of the liquid in which the solid is immersed

C

The upthrust is directly proportional to the volume of the fluid displaced by a solid

The upthrust acts on the body in upward direction at the center of buoyancy.

Upthrust is equal to the weight of liquid displaced by object and weight of liquid will depend on its density.

Upthrust is F=Vρg ,where V is the volume of liquid displaced and ρ is the density of fluid.

The total lateral pressure acting on an immersed object on one side is equal and in opposite direction to the total lateral pressure acting on the other side.

Answer:

Explanation:

There is no pressure of your feet on the scales, and no pressure of the floor on the scales, so the scales will read zero*. Hence, your weight, in a freely falling lift is zero

We know

[tex]\boxed{\sf Spring\:constant(K)=\dfrac{F}{x}}[/tex]

[tex]\\ \sf\longmapsto K=\dfrac{1}{0.5}[/tex]

[tex]\\ \sf\longmapsto K=2N/m[/tex]

Answer:

Wait until the end of the semester to complete all work.

Explanation:

this is the obvious answer.

please mark me brainliest

Answer:

Wait until the end of the semester to complete all work

Answer:

magnetic force:

i) It is exerted by a magnet.

ii)Magnetic forces are always normal to the direction of the velocity of the charge it acts upon.

Electrostatic force

i) It is exerted by electrically charged body.

ii)Electric force are independent of the direction the charge moves in.

✌✌✌✌