During first half of a journey by a body it travel with a speed of 40km/hr and in the next half it travels with a speed of 20 km/hr .Calculate the average speed of the whole journey.​

The energy responsible for temperature is referred as thermal energy. the movement of thermal energy from a warmer object to a cooler object is called heat.

Heat is energy that is transferred from one body to another as a result of a temperature difference.

When two bodies at different temperatures come into contact, energy is transferred (i.e., heat flows) from the hotter to the colder.

Thus, the correct option is A.

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Answer:

Hey there!

Kelvin is correct. Farenheit and Celsius are scales derived from the Kelvin scale. For example, K=C+273.15 is the conversion between Kelvin and Celsius.

Let me know if this helps :)

Answer:ball, ramp, and angle

Explanation: these are the three things that are controls because you can control them

Answer:

Yes

Explanation:

Scientific concept is a scientific theory or law that gives proof of how and why a natural event or process occurs.

Yes, scientific ideas and concepts can be changed because the research never stop and when scientists come with a new theory which is more strong than old theory, the old theory is required to be changed.

For example: In the scientific concept of classification of biodiversity, earlier organisms were classified into binomial system including plant and animal kingdoms but now we have five kingdoms that includes monera, protists, fungi,  plant and animal kingdoms.

Answer:

hello some parts of your question is missing below is the complete question

A 60.0 kg archer standing on a friction-less ice shoots a 100g arrow at a speed of 80.0 m/s to the right .When the arrow is released, how does the the force on the arrow (by the bow) compare to the force on the archer (by the bow)?

Answer : The force on the arrow is larger than the force on the archer because the arrow has a higher final velocity

Explanation:

we can compare The force on the arrow  to the force on the archer by using the final velocities of the archer and the arrow ,hence The force on the arrow is larger than the force on the archer because the arrow has a higher final velocity and this is according to Newton's law which states for a every action there is an equal reaction i.e the force applied on the arrow will be the opposite of the force on the archer

Answer:

Explanation:

A )

As the two bicycles come closer , the time period of oscillation of bee to oscillate between the two is gradually reduced . It is akin to a pendulum with gradually decreasing amplitude . It will be infinite number of trips the bee will travel before it gets squished .

B )

The bee will survive until the two bicyclists meet each other .

time of their meeting = distance between them / their relative velocity

= 20 / ( 10 + 10 )

= 1 hour .

C )

Total distance travelled by bee during 1 hour

= time x speed of bee

= 1 x 30 km/h

= 30 km .

Answer:

14.3 x 10^8Hz

Explanation:

Using

Frequency= speed of light /wavelength

Then substituting

3*10^8m/s / 0.21m

= 14.3 x10^8 Hz

Answer:

Level 4 to level 2

Explanation:

Electrons in an atom are contained in specific energy levels (1, 2, 3, and so on) having different distances from the nucleus. When light is emitted by electrons from one energy level to a lower level, level 4 to level 2 has the greatest energy.

Hence, the correct option is "Level 4 to level 2".

Answer:

No electric field will exist.

Explanation:

Given the following:

In other to for the proton to remain stationary in space, the electric field acting on the proton will be 0 or no electric field will exist. From the formulae ;

F = qE ; where q = charge of the particle

E = electric field intensity

The electric field force = F

At a stationary position in space, the electric field intensity = 0

F = qE = q * 0 = 0.

Also according to Heisinberg, measuring the momentum and position of a quantum object becomes more and more uncertain when measured simultaneously.

Here, one of position or momentum is know, measuring the electric field becomes very uncertain.

Answer: (1) 0.0 m

Explanation: In physics, displacement is defined as the change in position of a moving object. It is a vector, so has magnitude and direction, determined by a referential create to the system, i.e., the moving object. Mathematically, displacement is calculated by: [tex]\Delta x=x_{f}-x_{0}[/tex], in which:

For the basketball player, he runs 30m, 3 times, court and back. Assuming the initial position is 0:

[tex]\Delta x=0-0[/tex]

[tex]\Delta x[/tex] = 0.0

Since displacement is given by, only, the initial and final position and the player started at the initial point and ended at the initial point of the court, displacement is 0.

Answer:

9) This is a case of deceleration

10)-0.8 ms-2

b) acceleration is the change in velocity with time

11)

a) 100 ms-1

b) 100 seconds

12) 10ms-1

13) more information is needed to answer the question

14) - 0.4 ms^-2

15) 0.8 ms^-2

Explanation:

The deceleration is;

v-u/t

v= final velocity

u= initial velocity

t= time taken

20-60/50 =- 40/50= -0.8 ms-2

11)

Since it starts from rest, u=0 hence

v= u + at

v= 10 ×10

v= 100 ms-1

b)

v= u + at but u=0

1000 = 10 t

t= 1000/10

t= 100 seconds

12) since the sprinter must have started from rest, u= 0

v= u + at

v= 5 × 2

v= 10ms-1

14)

v- u/t

10 - 20/ 25

10/25

=- 0.4 ms^-2

15)

a=v-u/t

From rest, u=0

8 - 0/10

a= 8/10

a= 0.8 ms^-2

Answer:

The weight of the body on the other planet would be 200 N

Explanation:

Recall that the acceleration of gravity at sea level on Earth is obtained via the general Gravitational force formula when the distance "d" is the radius of the Earth (R):

[tex]F=m\,g=G\,\frac{m\,\,m_E}{R^2} = m \,(G\,\frac{m_E}{R^2} )[/tex]

We are told that the weight of the object on Earth is 450 N, that is:

[tex]W=m\,g= m \,(G\,\frac{m_E}{R^2} )= 450[/tex]

in this other planet the acceleration of gravity will be different as shown below:

[tex](G\,\frac{m_E\,(1/9)}{(R/2))^2} )=(G\,\frac{m_E\,\,4}{R^2\,\,9} )=\frac{4}{9} (G\,\frac{m_E}{R^2} )[/tex]

so, its gravity is 4/9 that of the Earth, which now we can use to convert its weight (w) on the planet as 4/9 the weight it has on Earth:

[tex]w=m\,g_p=m\,\frac{4}{9} \,g=\frac{4}{9} \,450= 200\,\, N[/tex]

Answer: atoms gain energy as a solid changes to a gas

Explanation:

Answer:

atoms gain energy as a solid changes to a gas

Explanation:

Answer:

t = 2.01 seconds

Explanation:

It is given that,

The acceleration of the elevator is 4.55 m/s².

We need to find time taken by you to reach a speed of 11 m/s

The initial velocity of the person is equal to 0 (at rest). Let t is the time.

Using equation of kinematics as follows :

v = u +at

Acceleration = g-a and u = 0

So,

[tex]t=\dfrac{v}{g-a}\\\\t=\dfrac{11}{10-4.55}\\\\t=2.01\ s[/tex]

So, 2.01 seconds is taken to reach a speed of 11 m/s.

Answer:

Direct proportionality

Explanation:

The graph of variables that are directly proportional such as the temperature and volume of a gas has a graph consisting of a diagonal line that from the lower left of the graph to the upper right of the graph

According to Charles law, the volume of a given mass of gas is directly proportional to its temperature in Kelvin at constant pressure

Charles law can be represented mathematically as V ∝ T

From which we have;

V₁/T₁ = V₂/T₂, therefore, the graph of V to T has a constant slope, ΔV/ΔT.

Answer:

v = 44.27 m / s

Explanation:

This is an exercise in kinematics since they ask the maximum speed of the train

           v² = v₀² + 2 a x

a train departs with zero initial velocity

           v² = 2 a x

           v = √ 2ax

calculate

           v = √ (2 1.21 810)

            v = 44.27 m / s

in this solution we have assumed that the train uses the entire distance with acceleration

Answer: the answer is true :-)

Explanation:

Explanation:

Given that,

Current passes through our chest is 0.3 A

The current persists for 3.06 minutes

We need to find the number of conduction electrons pass through your heart. Charge flowing divided by time equals current. Also, q = ne

[tex]I=\dfrac{ne}{t}\\\\n=\dfrac{It}{e}\\\\n=\dfrac{0.3\times 3.06\times 60}{1.6\times 10^{-19}}\\\\n=3.44\times 10^{20}[/tex]

So, [tex]3.44\times 10^{20}[/tex] electrons would pass through your heart.

Answer:

C. the area of the rectangle plus the area of the triangle under the line

Explanation:

Based on the information provided, the velocity vs. time graph is a line with a positive slope and a y-intercept of (0, 3).  The displacement is the area under this line.  This area can be divided into a triangle and a rectangle.  So of the options available, C is the correct one.

Answer:

C

Explanation:

There is no explanation for the answer.

Answer:

Cathode: The positive electrode of a cell. Cell: A single encased electrochemical unit (one positive and one negative electrode) which exhibits a voltage differential across its two terminals.

Answer:

Cell

Explanation:

A cell is a single encased electrochemical unit (one positive and one negative electrode) which exhibits a voltage differential across its two terminals.

Answer:

C) mass number

Explanation:

I got it correct on edge

Answer:  c

Explanation:

Answer:

The human retina can only detect incident light that falls in waves 400 to 720 nanometers long, so we can't see microwave or ultraviolet wavelengths. This also applies to infrared lights which has wavelengths longer than visible and shorter than microwaves, thus being invisible to the human eye.

Solution :-

Given :

Distance 1 = 30 km

Distance 2 = 70 km

We know that speed = distance/time

and, Average speed = total distance/total time taken

When the train acquired a speed of 30 km/hr, the time taken = 30/30 = 1 hour

Average speed = 9distance 1 + distance 2)/(time 1 + time 2)

AS time 2 or t2 is time taken for the second part of the journey of 70 km

⇒ 40 = 100/(1 + t2)

⇒ 40 + 40t2 = 100

⇒ 40t2 = 100 - 40

⇒ 40t2 = 60

⇒ t2 = 60/40

⇒ t2 = 1.5

So, t2 or time taken to travel the second part of the journey is 1.5 hours.

Speed of the second part of the journey = distance 2/time 2

⇒ 70/1.5

⇒ 46.666 km/hr or 46.7 km/hr.

Hence the answer is = 46.666 km/hr or 46.7 km/hr.

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Tysm!

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Answer:

1) F = 100N

2) a = 2 m/s²

3) m = 25 kg

Explanation:

1) F = ma ( F = ?, m = 10 kg, a = 10 m/s² )

  F = 10×10

  F = 100 N

2) F = ma ( F = 20N, m = 10 kg, a = ? )

   20 = 10×a

   10a = 20

   a = 20/10

   a = 2 m/s²

3)F = ma ( F = 100N, m = ?, a = 4 m/s² )

  100 = m×4

  4m = 100

  m = 100/4

  m = 25 kg

Hope that helps! Good luck!

Sir Isaac Newton was an English Mathematician,physicist,astronomer,theologian and author who is widely recognized as one of the most influential scientist of all time because of his discovery of gravity(force that attracts a body toward center of earth).

Answer:

Physical measures:  Reduction of internal friction,  high static friction tire system

chemist. : air-fuel ratio as efficient

Explanation:

A go-Kart is a vehicle that can be with a motor or with pedals, which is in contact with the ground.

Physical measures that help increase vehicle speed are:

* Reduction of internal friction, use bearings, with greased joints to reduce friction

* Decreased friction when forward creating an aerodynamic raindrop shape, sharp at the front and with a rapid descent at the rear, but without abrupt cuts to the geometry

* Path difference for air passing through the top and bottom, to create a downward force help lower the car by increasing speed

* A high static friction tire system so you can move faster on surfaces and take turns faster

* A shifting system to have an effective torque either pedal or motor, gear shifting system

From the point of chemist.

* Obtain an air-fuel ratio as efficient as possible to increase the force per unit of fuel.

Complete question is;

In a women’s 100-m race, accelerating uniformly, Laura takes 2.00 s and Healan 3.00 s to attain their maximum speeds, which they each maintain for the rest of the race. They cross the finish line simultaneously, both setting a world record of 10.4 s.

(a) What is the acceleration of each sprinter?

(b) What are their respective maximum speeds?

(c) Which sprinter is ahead at the 6.00-s mark, and by how much?

(d) What is the maximum distance by which Healan is behind Laura, and at what time does that occur?

Answer:

A) a_laura = 5.319 m/s² and a_healan = 3.745m/s²

B) V_max for laura = 10.638 m/s and V_max for Healan = 11.235 m/s

C) Laura is ahead of healan by 2.632 m

D) Healan is 4.471 m behind Laura

Explanation:

A) The distance traveled by each sprinter with constant acceleration would be gotten from the equation of motion which is;

s = ut + ½at²

Now, since they began at rest, thus, initial velocity(u) = 0 m/s

So, s = 0 + ½at²

s = ½at²

Now, maximum speed achieved by each of them is given by the formula;

v_max = u + at

Since u = 0, then;

v_max = at

Now, we are told that they set a world record of 10.4 s, thus;

Time taken by each to run at their maximum speed = (10.4 - t)

Distance travelled after attaining maximum speed = at + a(10.4 - t)

Thus;

Total distance covered by each sprinter = ½at² + (at)(10.4 - t)

Where;

t = time taken to accelerate to maximum speed

Since total distance covered is 100 m and she took 2 s to accelerate to max speed, then Acceleration for Laura would be calculated from;

100 = ½a(2)² + (2a(10.4 - 2))

This gives;

100 = 2a + 16.8a

18.8a = 100

a = 100/18.8

a_laura = 5.319 m/s²

Similarly, for Healan:

100 = ½a(3²) + (3a(10.4 - 3)

100 = 4.5 a + 22.2a

26.7a = 100

a = 100/26.7

a_healan = 3.745m/s²

B) From earlier we saw that max speed is;

v_max = at

Thus, for laura;

Vmax for laura= 5.319 × 2

V_max for laura = 10.638 m/s

Also, for healan;

Vmax = 3.745 × 3

V_max for Healan = 11.235 m/s

C) to find which sprinter is ahead at 6.00 s,

For Laura:

D = (½(5.319 × 2²)) + (2² × 10.638)

D_laura = 53.19 m

For Helen: D = (½(3.745 × 3²)) + (3 × 11.235) = 50.558 m

Difference = 53.19 - 50.558 = 2.632

Thus, Laura is ahead by 2.632 m

C) We are told that laura achieved max speed in 2 s while healan took 3 s. This means that when Laura had reached her maximum speed Healan was still accelerating. Thus;

From v_max = at

10.638 = (3.745)t

t = 10.638/3.745

t = 2.84 s

Distance travelled during this time is;

For Laura:

D = (½(5.319 × 2²) + (0.84)(10.638) = 19.574 m

Foe Healan:

D = (½(3.745 × 2.84²)) = 15.103 m

Difference = 19.574 - 15.103 = 4.471 m

Thus, Healan is 4.471 m behind laura

Answer:

he correct answer is 7       3 10⁻⁹ s

Explanation:

The speed of light is constant, so we can use the uniform motion ratios

         v = x / t

         t = x / v

let's calculate

        t = 1 / 2.9972 10⁸8

       t = 3.336 10⁻⁹ s

the correct answer is 7       3 10⁻⁹ s

Answer:

The total distance traveled is 28 inches.

The displacement is 2 inches to the east.

If an ant travels toward the right along a meter stick. If it starts at the 25.00 cm mark and then travels to the 80.00 cm mark, the distance covered by the and would be 55 centimeters and the displacement covered by the ant would be 55 centimeters as well.

Displacement describes this shift in location.

As given in the problem statement If an ant travels toward the right along a meter stick. If it starts at the 25.00 cm mark and then travels to the 80.00 cm mark, then we have to find the distance and the displacement covered by the ant,

For a straight linear motion in a single direction, the distance is equal to the displacement covered by the object.

Thus, the the distance covered by the ant would be 55 centimeters and the displacement covered by the ant would be 55 centimeters as well.

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Answer:

288 Joules

Explanation:

Work= delta kinetic energy. To find the work required to stop the kitten, you have to find the delta kinetic energy between when the kitten is moving and when it is stopped. Since it is not moving when it's stopped, it has no kinetic energy. So to find the work, just find the kinetic energy of the kitten moving at 12m/s.

KE=1/2((m)(v^2)), therefore

delta KE=(1/2)*((4kg)*((12m/s)^2))-0

The work done must this force do to stop the kitten will be "288 Joules". To understand the calculation, check below.

According to the question,

Mass of kitten, m = 4 kg

Speed, v = 12 m/s

Acceleration, a = 3 m/s²

We know the formula,

→ Kinetic energy, K.E = [tex]\frac{1}{2}[/tex] mv²

then,

→ ΔK.E = [tex]\frac{1}{2}[/tex] mv² - 0

By substituting the values, we get

           = [tex]\frac{1}{2}[/tex] × 4 × (12)² - 0

           = [tex]\frac{1}{2}[/tex] × 4 × 144 - 0  

           = 2 × 144

           = 288 Joules

Thus the above response is correct.

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