An athlete runs some distance before taking a long jump. Why ?​

Answer:

Kitchen B

Explanation:

This all boils Down to the phenomenon of convection current of àir where warmer air rises up and is replaced by cooler air, the fan is placed higher up in B and because hot air rises higher up it will remove more hot air here

Answer:

Leather Shoes, Microphones, Candles

Explanation:

Surprisingly, leather Shoes, Microphones, Candles were not mentioned in Stuff Matters a book written by Mark Miodownik which according to him explored "the marvelous things that shape our man-made world."

Answer:

Explanation:

Given the maximum speed limit on interstate 10 as 75 miles per hour, to get the speed in meter per seconds, we need to convert the given speed to meter per seconds.

Using the conversion 1 mile = 1609.34m and 1 hour = 3600 seconds

75 miles perhour = 75miles/1 hour

75miles/1 hour (in m/s) = 75miles*1609.34m* 1 hour/1mile * 1 hour * 3600s *

= 75 *1609.34m* 1 /1 * 1 * 3600s

= 120,700.5m/3600s

= 33.53m/s

Hence the maximum speed limit on interstate 10 in metre per seconds is 33.53m/s

Explanation:

Power = work / time

Power = force × distance / time

P = (12 kg × 10 m/s²) (8 m) / (10 s)

P = 96 Watts

The average power used in raising the bucket against the gravitational force is equal to 94.08 W.

Power can be defined as the rate of doing work in unit time. The S.I. unit that is used to measure power is Watt (W) or Joule per second. Power can be described as the rate at which work is done.

Power = Work /time

Given, the mass of the bucket, m = 12 kg

The distance traveled by the bucket, d = 8 m

The work is done by the bucket, W = F.d

W = mg.d

W = 12 × 9.8 ×8

W = 940.8 J

Given, the time is taken by the bucket, t = 10 s

The power used in raising the bucket against the gravitational force:

P = W/t

P = 940.8/10

P = 94.08 W

Therefore, the average power is equal to 94.08 W.

Learn more about power, here:

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Answer:

The observer will say that galaxy 2 is moving away from galaxy 3 where he stands.

Explanation:

Since the galaxies are expanding, each one would move away from the others. Observers on all three galaxies have their frame of reference fixed on their own galaxies. Judging from their own galaxies, each observer will perceive the other galaxies moving away from his/or galaxy.

The observer at galaxy 3 will talk about galaxy 2 by doing is; he will say that galaxy 2 is moving far from him.

We are told that the universe is expanding and as such, the galaxies would be expanding and moving away from each other.

Since the galaxies are expanding, it means that they will be moving away from each other.

From time dilation principle, an observer at galaxy 3 will say that galaxy 2 is moving far from him.

Read more about galaxies at; https://brainly.com/question/21413373

Answer:

1) Joe's hypothesis was that the baking powder he used was too old and that was why the cake did not rise

2) Joe concluded that the baking powder was not the cause of the cake not rising

3) Joe observed that the cake he made for his mother's birthday did not rise

4) The independent variable was the baking powder

5) The dependent variable was the rising cake

6) Joe's control in the experiment was the extra cake made using the same ingredient as the first

7) The constants were the heat and time to bake both cakes

8) He should recheck all the variables and constants (recipes and procedures) are correct as can be found in baking books

Explanation:

Answer: Please find the answers in the explanation

Explanation:

From the given description, when Joe noticed that the cake had not risen,  he guessed that the baking powder he had used was too old.

Hypothesis is one of the scientific methods which means guessing.

What is Joe's hypothesis?

Joe's hypothesis is that the baking power used was not effective to make the cake rise believing that it was too old.

After Joe prepared two cakes, one using the same ingredients as his first cake and one using fresh baking powder. After preheating the oven to 350°F, he placed both cakes in the oven for 30 minutes. After 30 minutes, he removed both cakes and noticed that neither one had risen. He decided that the baking powder wasn’t the cause of his problem.

What is Joe's conclusion?

The conclusion is that the inability for the cake to rise wasn't as a result of ineffectiveness of the baking powder used.

What did Joe’s observe?

Joe observed that the cake had not risen.

What was the independent variable in Joe’s experiment?

The independent variable determines the dependent variable.

The independent variable is therefore, the different types of baking powder used.

What was the dependent variable in Joe’s experiment?

The dependent variable is the volume of the cakes.

What was the control in Joe’s experiment?

Joe was able to control the time and the temperature.

What were the constants in Joe’s experiment (assuming he did it correctly)?

The constant were the quantities of the cake ingredient, time used, and the temperature

8. Based on his conclusion, what should Joe do next?

Joe can try another ingredient like yeast or reconsider the ratio of the baking powder to the flour.

Answer:

The frequency will still remain F

Explanation:

Firstly, we should remember that the frequency of a simple harmonic oscillator doesn't depend on the amplitude. Rather, it depends on the spring constant, k, and the mass of the attached weight, m. This means that the change in amplitude will not lead to a corresponding change in frequency.

the frequency is represented by the formula

f = 1/2π * √(k/m),

where

f = frequency of the oscillator

k = spring constant and

m = mass attached to the spring

From the formula above, we can state that the frequency doesn't depend on the amplitude at all, and as such, the amplitude changing from A to 2A, will effect no change in the frequency F.

Answer:

a) La aceleración del movimiento es 1 metros por segundo al cuadrado, b) La fuerza que causa el movimiento es 80.000 newtons.

Explanation:

a) Supóngase que la locomotora acelera uniformemente, la aceleración se está descrita por la siguiente ecuación cinemática:

[tex]v = v_{o}+a\cdot t[/tex]

Donde:

[tex]v_{o}[/tex] - Rapidez inicial, medida en metros por segundo.

[tex]v[/tex] - Rapidez final, medida en metros por segundo.

[tex]a[/tex] - Aceleración, medida en metros por segundo al cuadrado.

[tex]t[/tex] - Tiempo, medido en segundos.

Se despeja la aceleración:

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

Si [tex]v_{o} = 0\,\frac{m}{s}[/tex], [tex]v = 10\,\frac{m}{s}[/tex] y [tex]t = 10\,s[/tex], la aceleración del movimiento es:

[tex]a = \frac{10\,\frac{m}{s}-0\,\frac{m}{s}}{10\,s}[/tex]

[tex]a = 1\,\frac{m}{s^{2}}[/tex]

La aceleración del movimiento es 1 metros por segundo al cuadrado.

b) Dado que una locomotora es un sistema de masa constante, la fuerza ([tex]F[/tex]) que genera el movimiento es igual a:

[tex]F = m\cdot a[/tex]

Donde:

[tex]m[/tex] - Masa, medida en kilogramos.

[tex]a[/tex] - Aceleración, medida en metros por segundo al cuadrado.

Dados que [tex]m = 80.000\,kg[/tex] y [tex]a = 1\,\frac{m}{s^{2}}[/tex], la fuerza que causa el movimiento es:

[tex]F = (80.000\,kg)\cdot \left(1\,\frac{m}{s^{2}} \right)[/tex]

[tex]F = 80.000\,N[/tex]

La fuerza que causa el movimiento es 80.000 newtons.

Answer:

Reaction force

Explanation:

According to Newton's third law of motion, for every action, there is an equal opposite reaction.

Hence the reaction force is often equal in magnitude to the applied force but acts in a direction opposite to the direction of the applied force.

Hence, when a baseball player, gets a hit, the ball exerts a reaction force on the player which is equal in magnitude to the force with which the player hits the ball but opposite in direction.

Answer:

a

Explanation:

............

..............option A

Answer:

A is the answer as electromagnetic and strong nuclear forces influence the interaction between charged particles within an atom the only difference being their intensity! Hope this helps :) and if you dont mind, mark me brainliest so i can get to the next rank :(

Answer:

The amount of gravity affecting an object depends on two things: the masses of the objects being attracted and the distance between the objects. Mass is the measure of the amount of matter in an object. With distance, we see that the strength of gravity decreases if the distance between two objects increases.

Hope this helps!

Answer:

The maximum speed of the oscillating object doubles as well.

Explanation:

The oscillatory motion of the object on the spring can be modelled using this equation below:

[tex]Vmax= A\omega[/tex]

Where

Vmax = the maximum speed of the oscillating object.

A = Amplitude of the oscillating object.

[tex]\omega[/tex] = angular velocity of the oscillating object.

If the amplitude, A becomes doubled, the new amplitude will be = 2A.

As a result,  [tex]Vmax = 2 A \omega[/tex]

This shows that the maximum speed has doubled in its value

Your question has been heard loud and clear.

Well , basically anything that moves in a certain direction is an example of unbalanced forces.

When we kick the football , the force given by our leg is greater than the frictional force by the ball and therefore the ball moves in the direction of the greater force , which is the force given by our leg.

Thank you

Answer:

friction

Explanation:

Answer:

[tex]\boxed{\sf Position \ of \ the \ image = 6 \ cm}[/tex]

[tex]\boxed{\sf Nature \ of \ the \ image = Virtual \ and \ Erect}[/tex]

Given:

Object distance (u) = -10 cm

Focal length (f) = 15 cm

To Find:

Image distance (v) and nature of the image

Explanation:

Mirror Formula:

[tex]\boxed{\bold{\sf \frac{1}{v} + \frac{1}{u} = \frac{1}{f}}}[/tex]

Substituting values of u and f in the equation:

[tex]\sf \implies \frac{1}{v} -\frac{1}{10} =\frac{1}{15}[/tex]

[tex]\sf \implies \frac{1}{v}=\frac{1}{15} +\frac{1}{10}[/tex]

[tex]\sf \implies \frac{1}{v}=\frac{2}{30}+\frac{3}{30}[/tex]

[tex]\sf \implies \frac{1}{v}=\frac{2+3}{30}[/tex]

[tex]\sf \implies \frac{1}{v}=\frac{5}{30}[/tex]

[tex]\sf \implies v=\frac{30}{5}[/tex]

[tex]\sf \implies v=6 \ cm[/tex]

[tex]\therefore[/tex]

Image distance (v) = 6 cm

Nature of the image = Virtual and Erect

Answer:

True, yes terminal voltage of a battery can never be greater than the emf of the battery. Because due to internal resistance of the current terminal

when object goes under acceleration

c).its velocity always increases

★ Acceleration: Rate of increase in velocity.

★ Velocity: Distance travelled by a body per unit time in given direction is called velocity .

Answer: velocity always increase

Explanation: Really dont need any explanation

Answer:

El alcance de la bala es 3464,1 m.

Explanation:

El alcance de la bala se puede calcular como sigue:

[tex]y = y_{0} + tan(\theta)*x - \frac{g}{2}*\frac{x^{2}}{(v_{0}cos(\theta))^{2}}[/tex]

En donde:

y: es la altura final = 0

[tex]y_{0}[/tex]: es la altura inicial = 0

x: es el alcance

θ: es el angulo respecto a la horizontal = 30°

[tex]v_{0}[/tex]: es la velocidad inicial = 200 m/s

g: es la gravedad = 10 m/s²

Entonces, tenemos:

[tex] y = y_{0} + tan(\theta)*x - \frac{g}{2}*\frac{x^{2}}{(v_{0}cos(\theta))^{2}} [/tex]

[tex] x = \frac{2tan(\theta)*(v_{0}cos(\theta))^{2}}{g} = \frac{2tan(30)*(200 m/s*cos(30))^{2}}{10 m/s^{2}} = 3464,1 m [/tex]

Por lo tanto, el alcance de la bala es 3464,1 m.

Espero que se te sea de utilidad!

Answer:

4 m/s East.

Explanation:

Velocity: This cam be defined as the rate of change of displacement. The unit of velocity is m/s.

From the question,

v = d/t...................... Equation 1

Where v = velocity, d = displacement, t = time.

Given: d = 20 m East, t = 5 seconds.

substitute into equation 1

v = 20/5

v = 4 m/s East.

Hence the average velocity = 4 m/s East.

Explanation:

Given that,

Force with which a child hits a ball is 350 N

Time of contact is 0.12 s

We need to find the impulse received by the ball. The impulse delivered is given by :

[tex]J=F\times t\\\\J=350\times 0.12\\\\J=42\ N-m[/tex]

So, the impulse is 42 N-m..

We know that he change in momentum is also equal to the impulse delivered.

So, impulse = 42 N-m and change in momentum =42 N-m.

Answer:

net 5N of force will act in east direction.

Explanation:

force acting in North and South direction will cancel each other.

force in east direction - force in west direction = 5N

Answer:

Solution

Load(L)=400

Effort(E)=100

Load distance (Ld)=20cm

Effort distance(Ed)=?

Now,from the principle of equilibrium

L×Ld=E×Ed

or,Ed=L×Ld/E

or,Ed=400×20/100

:.Ed=80cm and

Therefore,the effort distance will be 80cm

Answer:

80cm

Explanation:

load l = 400

Effort e = 100

load distance Ld = 20

Effort distance Ed = ?

L×ld= E×Ed

Ed=L×Ld \ E

Ed=400×20/100

Ed=80cm Ans

standerd unit of time is second

Answer:

The standard unit for time is second (s).

[tex] \bf \underline{ \underline{given : }}[/tex]

[tex]\bf \underline{ \underline{to \: be \: calculated : }}[/tex]

Calculate the distance covered by a kangaroo.

[tex]\bf \underline{ \underline{formula \: applied : }}[/tex]

[tex] \boxed{ \bf{Speed = \frac{Distance}{Time} }}[/tex]

[tex]\bf \underline{ \underline{Solution : }}[/tex]

We know that,

Speed = Distance/Time

=> Distance = Speed × Time

Substituting the values in the above formula,we get;

=> Distance = 18 × 192

=> Distance = 3456 m

Thus,the distance covered by a kangaroo is 3456 meters.

Answer: In places of hot climate it is advised that the outer wall of houses be painted white because white color reflects heat and the houses do not heat up too much.

Answer:

Explanation:

Both small ball and a basketball are in form of a sphere. Total surface area of a sphere is gotten using the formula;

surface area of a sphere S = 4πr²

If the radius of a small ball is around 2.8436 cm, its total surface area will be:

S = 4π(2.8436)²

S =4π(8.086)

S = 101.61 cm²

If the radius of a basketball is about 4.22 times larger, the radius will be 4 times larger as well. The radius of the basket ball = 4.22*2.8436

radius of thr basketball = 11.99cm

Surface area of the basketball S2 =  4π(11.99)²

S2 =4π(143.76)

S2 =1806.54cm²

The ratio of the surface areas of the small ball and a basketball S:S2

S:S2 = 101.61 cm² : 1806.54cm²

S:S2 = 0.0562

Hence, the ratio of the surface areas of the small ball and a basketball is approximately 0.0562.

2) The volume of a sphere = 4/3πr³

Volume of the small ball = 4/3π(2.8436)³

Volume of the small ball = 4/3 π  * 22.994

Volume of the small ball= 96.315cm³

Similarly;

Volume of the basketball = 4/3π(11.99)³

Volume of the small ball = 4/3 π  * 1723.68

Volume of the small ball= 7220.14cm³

The ratio of the volume of the small ball and a basketball V:V2

V:V2 = 96.315  : 7220.14

V:V2 = 0.01333

Hence, the ratio of the volumes of the small ball and a basketball is approximately 0.01333

Answer:

236.22 inches

Explanation:

There are 39.3701 inches in 1 meter.  So to find 6 meters, multiply 6 times 39.3701.

6·39.3701=236.22

Answer:

236.22

Explanation:

just because itit's common sense

Answer:

0.4m/s

Explanation:

It is given speed so it is scalar.

distance covered in 1 round = 180m

therefore, distance covered in 4 rounds = 180*4 = 720m

time = 30 mins = 30*60 = 1800 seconds

average speed = total distance/total time taken

= 720/1800

= 0.4m/s

Answer:

B. Gravity and air resistance

Explanation:

Experimentation has proven that :

When the parachute opens, air resistance becomes much greater than gravity. The forces are no longer balanced and this changes the

speed

Answer:

[tex]\large \boxed{\mathrm{B. \ Gravity \ and \ air \ resistance}}[/tex]

Explanation:

Gravity and air resistance are the forces that get balanced out during a free fall. This is also known as terminal velocity, when gravity = air resistance.

Answer:

[tex] \boxed{\sf Density \ of \ the \ substance = 10.5 \ g/cm^3} [/tex]

Given:

Mass (M) = 7917 grams

Volume (V)= 754 cm³

To Find:

Density of the substance

Explanation:

[tex] \boxed{ \bold{\sf Density \ (\rho) = \frac{Mass \: (M)}{Volume \: (V)}}}[/tex]

Substituting values of M & V in the equation:

[tex] \sf \implies \rho = \frac{7917}{754} [/tex]

[tex]\sf \implies \rho = 10.5 \: g/ {cm}^{3} [/tex]

Explanation:

Acceleration is the change in velocity over change in time.

a = Δv / Δt

So it is the slope of the line of a velocity vs. time graph.

a = (10 m/s − 40 m/s) / (12 s − 0 s)

a = -2.5 m/s²