A robot standing on a cliff shoots a ball upwards with an initial speed of 30 m/s. What is the height of the cliff given that the ball reaches the bottom of the cliff 8 s after the shoot? (Take g = 10 m/s^2 and the height of the robot is negligible.)
A 25 m
B 45 m
C 80 m
D 145 m​

Answer:

4.61 N

Explanation:

masa = 0.5 kg

ángulo de inclinación = 20°

Peso normal de la masa = mg

donde m = masa

g = aceleración debido a la gravedad = 9.81 m/s^2

Peso normal = 0.5 x 9.81 = 4.905 N

Si la masa se mantiene en su lugar mediante una cuerda paralela al plano, y no hay fricción en la masa, entonces

La fuerza sobre la cuerda = peso normal x cos ∅

donde ∅ = 20 °

La fuerza sobre la cuerda = 4.905 x cos 20°

==> 4.61 N

Answer:

a)  True    b)  True

Explanation:

a) a capacitor is made up of two flat plates and each one has a charge of the same sign, therefore the statement is true

b) the current is the flow of electrons per unit of time, therefore the charge is not zero, therefore the statement is True

Answer:

Period of the signal.

Explanation:

So, this question is all about a concept in physics or astronomy which is called or known as Radiation Astronomy and Galactic Nuclei that are active. This concept talks most about Quasars; a powerful radiating object which derives its power from black holes.

When You take a look at Quasars, we get the to know that the more you think you can see, the more they move away from us.

Thus, when "You are observing the radiation from a distant active galaxy and you notice that the amplitude of the signal varies in strength regularly over a certain period. The maximum possible size for the source of this radiation can now be calculated from the "PERIOD OF THE SIGNAL.

NB: not the amplitude but the period.

Answer:

C and D

Explanation:

A: is a simple composition

B: is a single replacement

C: C is a double displacement

D: is a double replacement

Answer:

The answers are C abd D.

Explanation:

Here,

A no. Is a combination or analysis chemical reaction.

B no.is a single displacement reaction as cl2 goes to zn.

C no. Is double displacement reaction.

D no. Is a double displacement reaction.

Hope it helps.....

The statement that is the most true regarding the states of matter is the first statement.

A. Most matter on Earth exists as a solid, liquid, or gas.

This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.

Therefore, B is incorrect.

C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.

D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.

Matter can be defined as the material substance which constitutes the observable nature. Most matter on Earth exists as a solid, liquid, or gas. Plasma is also the state of matter found in daily life. The correct option is A.

All the materials which we see in our daily lives are made up of matter. Matter can be classified into different states such as solid, liquid and gas based on the intermolecular forces and the arrangement of particles. All the three states of matter can be converted from one form to another.

The molecules of solid are tightly packed and they have strong intermolecular forces which also has a definite shape and volume. The liquids have weak intermolecular forces than the solids and it acquire the shape of the vessel.

The intermolecular forces in gases are negligible and they do not have any fixed shape or volume.

Thus the correct option is A.

To know more about states of matter, visit;

https://brainly.com/question/1134312

#SPJ2

Answer: Contant.

Explanation:

You are given that When the boat moves the force of resistance is proportional to the velocity of the boat. This means that the total momentum on the boat is equal to zero. Then the boat remains at a certain position.

When a person walks from the stern to the bow of the boat, the boat will tend to move in the opposite direction with equal magnitude of momentum. The magnitude of forces will thereby cancel out.

The person will be seen moving while the boat moves in the opposite direction.

If no external force is acting on the boat, the sum of the momentum of the person and the boat will be equal to zero. And the boat will remain at rest.

The position of the boat long time after the person stopped moving will therefore remain the same.

Answer:

The patient is suffering from protein deficiency

Explanation:

Protein deficiency is characterized by symptoms such as stunted growth; skin, nail and hair problems, loss of muscle mass, and in extreme cases, kwashiorkor.

Deficiency in protein is usually corrected by taking foods rich in protein such as egg's albumin, milk, pulses, beans, etc; hence the advice of the doctor.

Answer:

Vi = 5 m/s

Explanation:

let (a) acceleration = 0.75 m/s²

(t) time = 20 seconds

Vf = final velocity = 72 km/hr  (convert to m/s to units consistency = 20 m/s)

find Initial velocity (Vi)

       Vf - Vi

a =  -----------

             t

Vi = Vf - (a * t)  = 20 - (0.75 * 20)

Vi = 5 m/s

Explanation:

In recent times of pandemic, robots can be use as replacement of labor in the industries. Mundane tasks can be programmed in their system so that they can used readily.

Drones can used delivery for essential goods and services, so that human interference can be least and the spread of virus can be curbed.

In a recent example, Argentina where aerial data has reportedly been used to accelerate the construction of emergency hospitals.

Answer:

Los datos que tenemos:

Rapidez: 69km/h

Tiempo que tarda en frenar = 4s.

Distancia inicial entre la tracto-mula y la vaca = 25m

Ok, la ecuación de desaceleración es:

D = (sf - si)/t

sf = velocidad final = 0m/s

si = velocidad inicial = 69km/h

t = tiempo = 4s

D = -69km/h/4s

ok, 1h = 3600s

D = (-69km/s)*1/(4*3600s)  = -0.0048 km/s^2

Entonces la ecuación de aceleración es:

a(t) =  -0.0048 km/s^2

Para la velocidad, integramos sobre el tiempo

v(t) = (-0.0048 km/s^2)*t + v0

donde v0 es la velocidad inicial, en este caso v0 = 69km/3600s = 0.0191km/s  

v(t) =  (-0.0048 km/s^2)*t + 0.0191km/s

Para la posición volvemos a integrar sobre el tiempo, esta vez suponemos la posición inicial igual a cero.

p(t) = (1/2)*(-0.0048 km/s^2)*t^2 + 0.0191m/s*t

Ahora, si p(t=4s) < 25m, esto implica que la tracto-mula no impacto con la vaca.

p(4s) = (1/2)*(-0.0048 km/s^2)*(4s)^2 + 0.0191km/s*4s = 0.038km

y 1km = 1000m

0.038km = 0.038*1000m = 38m

Entonces si, atropello a la vaca.

Answer:

[tex] 2.18\times 10^{-30} \:J[/tex]

Explanation:

[tex] K.E._{Electron}= \frac{1}{2} mv^2 \\\\

= \frac{1}{2} \times 9.11\times 10^{-31}\times (2.19\times 10)^2 \\\\

=4.555\times 10^{-31}\times 4.7961\times 10^2 \\\\

=4.555\times 10^{-31+2}\times 4.7961 \\\\

=21.8462355\times 10^{-29}\\

=2.18462355\times 10^{-30}\\

=2.18\times 10^{-30} \:J\\[/tex]

Answer:

Explanation:

In physics, there are two types of physical quantities namely the fundamental and the derived quantities. Fundamental quantities are independent quantities on which derived quantities depends on. Length, mass and time are examples of fundamental quantities.

The SI unit of length is meters. A meter is a multiple unit. Its submultiple units are centimetres (10⁻²metres), kilometres (10³metres), decimetres (10⁻¹metres) etc

The SI unit of mass is kilogram (kg). The only sub multiple unit used in real-life situation is grams.

1 kg = 100 grams

The SI unit of time is seconds. The multiple units are the minutes, hours, weeks, days and years.

1 minute = 60 seconds

1 hour = 3600 seconds

1 day = 24 * 3600 = 86,400 secs

Answer:

Hello There. ☆~\《--_^■^_--》\~☆ The final velocity of the car A is -1.053 m/s. For an elastic collision both the kinetic energy and the momentum of the system are conserved.

Hope It Helps!~ ♡

ItsNobody~ ☆

Given:

[tex]M_A = 281 \ kg \\\\ v_A= 2.82 \frac{m}{s}\\\\M_B = 209 \ kg \\\\ V_B = 1.72 \frac{m}{s}[/tex]

To find:

velocity=?

Solution:

Using the formula for the velocity of CAR after the collision:

[tex]\to V_A = \frac{V_A(M_A -M_B) +2 M_B V_B}{M_A+M_B}\\\\[/tex]

         [tex]= \frac{2.82(281 - 209) +2 \times 209 \times 1. 72}{ 281+ 209}\\\\ = \frac{2.82(72) +718.96}{490}\\\\= \frac{203.04 +718.96}{490}\\\\= \frac{922.00}{490}\\\\= \frac{922}{490}\\\\=1.881 \ \frac{m}{s}[/tex]

Therefore, the answer is "[tex]\bold{1.881\ \frac{m}{s}}[/tex]"

Learn more about the velocity:

brainly.com/question/24376522

u=10m/s

v=15m/s

acceleration=

v_u/ t

5/10

0.5

Answer:

a) wavelength for the two frequencies are 0.33 m and 0.12 m

(b) 2560 MHz

Explanation:

Given:

microwave frequencies are

900 and 2560 MHz

f1= 900MHz we need to convert it to Go so the unit will be able to be consistent

f1= 900MHz= 900× 10^6Hz

f2= 2560 MHz= 2560×10^6Hz

a)Calculate the wavelength of each

But we can calculate our wavelength λ using the below formula

λ=c/f

c which is the speed of light has a constant value of =3*10^8m/s

Then for the first frequency

λ=c/f =(3×10^8)/900×10^6

=0.33 m

=33 cm.

For the second frequency

λ=c/f = (3×10^8)/2560×10^6

=0.12 m

=12 cm

(b) Which frequency would produce smaller hot spots in foods due to interference effects

(b) 2560 MHz( has the smallest wavelength)

This is because a small wavelength microwave gives a pattern with which is interference with waves and have a closer hotspot

Answer:

72.16 N

Explanation:

Given:

q₁ = -53.0 μC

q₂ = 105 μC

q₃ = -88.0 μC

q₁ to q₂ = 0.50 m

q₂ to q₃ = 0.95 m

To find:

Net force on q₃

Solution:

First compute net electric field on q₃

E = F/q = k.Q/d²

The formula of electric field at q₃:

E = k.Q / r²

Where    

r is distance

Q is magnitude of charge

k is a constant with a value of 8.99 x 10⁹ N m²/C²

When

q₂ to q₃ = 0.95m and

q₂ = 105 μC then

Find electric field due to charge q₂

E = ( (8.99 x 10⁹)x( 105 x 10⁻⁶) ) / 0.95²

  =  (8990000000  x 0.000105) / 0.9025

  = 943950  / 0.9025

  = 1045927.977839

  = 1.046 x 10⁶ N/C

This interprets that it will act or point away from q₂

q₁ to q₂= 0.50m

q₂ to q₃ = 0.95m and

q₁ = -53 μC then

Find electric field due to charge q₁

E = (8.99 x 10⁹) x (53 x 10⁻⁶) / (0 .50 + 0.95)²

  =  (8990000000  x  0.000053) / (1.45)²

  = 476470 /2.1025

  = 226620.689655

  = 0.227  x 10⁶ N/C

This interprets that it will act or point towards q₁

Since these fields are opposite in direction.

Compute Net Field

Net Field = 1.046 x 10⁶ - 0.227  x 10⁶ N/C

               =  1046000 - 227000

               = 819000

               = 0.819 x 10⁶

               ≈ 0.82 x 10⁶

This interprets that it will act or point away from q₂

Compute force on q3

q₃ E  = 88 x 10⁻⁶ x 0.82 x 10⁶

       = 88000000  x 820000

       = 72160000000000

       = 72.16 N

Force on -ive charge in a field is always in a direction opposite to direction of field

So this interprets that direction of this field will be towards q₂.

Answer:

You turn on the burner of a gas or stove - mechanical energy.

The gas ignites - Chemical energy.

The gas warms the water in the pan - Thermal energy.

Answer:

Technician B only is correct

Explanation:

The gear ratio is the ratio of the output speed to the input speed such that an overdrive gear ratio of more than 1:1, having more speed per speed of engine rotation RPM

Overdrive ratios conditions is one where the vehicle wheels and speed is faster at a given engine rotation, such that there is fuel efficiency is increased as the engine rotation is low for a given speed and distance of travel.

Answer:

culture

food

Explanation:

The above mentioned studied the interaction between food and culture. Food habits reflect different meanings in different cultures. As per the question, the United States America and Japan are two countries far away from each other, which have distinct cultures and gave rise to different eating norms. However, the impact of media have been shaping the eating patterns around the globe, which have brought different food and cultures together.

Answer:

The hotter star radiates 625 times more energy per second from each square meter of its surface

Explanation:

Temperature of the hotter star is 30000 K

temperature of the cooler star = 6000 K

From Stefan-Boltzmann radiation laws, for a non black body

P = εσA[tex]T^{4}[/tex]

where

P is the energy per second or power of radiation

ε is the emissivity of the body

σ is the Stefan-Boltzmann constant of proportionality

A is the area of the sun

T is the temperature of the sun

The sun can be approximated as a black body, and the equation reduces to

P = σA[tex]T^{4}[/tex]

For the hotter body,

P = σA([tex]30000^{4}[/tex]) = 8.1 x 10^17σA  J/s

For the cooler body,

P = σA([tex]6000^{4}[/tex]) = 1.296 x 10^15σA   J/s

comparing the two stars energy

==> (8.1 x 10^17)/(1.296 x 10^15) = 625

This means that the hotter star radiates 625 times more energy per second from each square meter of its surface

Answer:

 K = 9.53 MeV

Explanation:

The kinetic energy that the alpha particle has emitted, is the energy in excess after removing the resting energy of the atoms and the helium nucleus that forms the alpha particle

Since energy and masses are related and cannot be

          m₀ c² = [tex]m_{f}[/tex] c² + m_He c²+ K

          K = c² (m₀ - m_{f} - m_He)

the mass of the Helium atom is 4 u

           K = (3 10⁸)² (211,988868 -207.976652 - 4,002) 1,661 10⁻²⁷

           K = 14,949 10⁻¹¹ (0.0102)

          K = 1,527 10⁻¹² J

let's reduce 1 J = 6,242 10¹² MeV

           K = 9.53 MeV

Answer:

The correct option is (a) "Changing".

Explanation:

If a coil is placed in the magnetic field, due to the change in its magnetic flux an emf will induce in it. EMF is like voltage. So, due to the induced emf and current is induced in it. Hence, we can say that changing the magnetic field can create an electric current.

Answer:

Using X = sum( x's * mass)/sum( masses)

= [(0)*(6400)+ (-9.5*1000) + (9.5)*(1000) + (9.5)*(1000)]/(6400+1000+1000+1000)

= 1.01 m

Y = sum( y's * mass)/sum( masses)

= [(0)*(6400) + (9.5)*(1000) +(-9.5)*(1000) + (-9.5)*(1000)]/ (6400+1000+1000+1000)

= -1.01 m

Answer:

Measurement is inevitable because in every single thing we do we measure.for instance, if you are a family of four,the food prepared will be less than the food prepared for a family of about 15 people.this is measurement.if not so,the food prepared will go waste.again, the drugs prescribed by the doctor is measured to avoid over dose or under dose of medication.this can be harmful to ones health

Answer:

(d) Water has a high specific heat.

Explanation:

At night, when the temperature of earth goes down due to loss of heat , the temperature of water is lost slowly and temperature of land is lost fast because of high specific heat of water . Water loses as well as gains temperature comparatively slowly due to its high specific heat .

During daytime when earth gains heat , the temperature of land rises more rapidly than water so water appears cool even during daytime when land becomes  hotter . It is also due to high heat holding capacity of water or due to high specific heat of water .

Answer: 29.72

Explanation:

you multiply the number by 5 then divide by 18=

107x5= 535

535/18= 29.72

Answer:

37.8 m

Explanation:

At point 0, the ball is at height y₀.

At point 1, the ball is at height 30 m.

At point 2, the ball is at height 0 m.

Given:

y₁ = 30 m

y₂ = 0 m

v₀ = 0 m/s

a = -10 m/s²

t₂ − t₁ = 1.5 s

Find: y₀

Use constant acceleration equation.

y = y₀ + v₀ t + ½ at²

Evaluate at point 1.

y₁ = y₀ + v₀ t₁ + ½ at₁²

30 m = y₀ + (0 m/s) t₁ + ½ (-10 m/s²) t₁²

30 = y₀ − 5t₁²

Evaluate at point 2.

y₂ = y₀ + v₀ t₂ + ½ at₂²

0 m = y₀ + (0 m/s) t₂ + ½ (-10 m/s²) t₂²

0 = y₀ − 5t₂²

y₀ = 5t₂²

Substitute:

y₀ = 5 (1.5 + t₁)²

y₀ = 5 (2.25 + 3t₁ + t₁²)

y₀ = 11.25 + 15t₁ + 5t₁²

30 = 11.25 + 15t₁ + 5t₁² − 5t₁²

30 = 11.25 + 15t₁

t₁ = 1.25

30 = y₀ − 5t₁²

30 = y₀ − 5(1.25)²

y₀ ≈ 37.8

Answer:

distance between two points having phase difference 5.6 rad is

Φ = 2.33 m

Explanation:

given

frequency, f = 130Hz

speed of sound in air, v = 340m/s

distance between two crust or through with phase difference 2[tex]\pi[/tex] = λ (wavelength)

phase difference = 5.6 rad

note: distance between two points having a phase difference = [tex]\frac{ \lambda }{2\pi }[/tex]

∴ distance between two points having phase difference of 5.6 rad is = [tex]\frac{ \lambda }{2\pi }[/tex] ×5.6

Recall

v = f × λ

speed = frequency × wavelength

wavelength = speed/frequency

λ  = v/f

λ  = 340/130 = 2.615 m

∴ distance between two points having phase difference 5.6 rad is = [tex]\frac{ 2.615 }{2\pi }[/tex] ×5.6 = 2.33 m