a.
more iOCUS
8.
A force of 8N is applied to the body to cover 50 cm distance. How much work is done
by this fore?
400J
b. 40J
d. 40kg
a.
C.​

Answer:

(B) Parachutes

Explanation:

Air resistance works to slow down trains and airplanes, so it isn't desirable.  Air resistance also causes pendulums to slow and stop.

Parachutes need air resistance to slow a person's fall.  So air resistance is desirable here.

Answer:

B i answered it it it

Explanation:

Answer: Efficiency signifies a peak level of performance that uses the least amount of inputs to achieve the highest amount of output.

Explanation: It minimizes the waste of resources such as physical materials, energy, and time while accomplishing the desired output.

Answer:

The efficiency of a simple machine is defined as the ratio of useful work done by the machine ( output work) to the total work out into the machine ( input work).

Explanation:

If a machine overcomes a load ' L ' and the distance travelled by the load is 'Ld' , the work done by the load is L× LD. It is also called output work or useful work.

Therefore, [tex] \boxed{Output \: work \: = L \: \times \: Ld}[/tex]

Likewise, The effort applied to overcome the load is 'E' and the distance covered by effort is 'Ed' , the work done by effort is E × Ed. It is also called input work.

Therefore, [tex] \boxed{Input \: work = E \times Ed}[/tex]

The efficiency of a simple machine is defined as the ratio of output work to the input work .

Therefore, [tex] \boxed{Efficiency ( η)= \frac{outpt \: work}{input \: work} \times 100\%}[/tex]

Efficiency is expressed in percentage. It is a ratio of two works. A machine is never 100% efficient. It is because no machine is friction free and due to friction, some of the input energy is wastes in the form of heat energy.

[tex] \mathrm{Hope \: I \: helped!}[/tex]

[tex] \mathrm{Best \: regards!}[/tex]

Answer: A) an upward force balances the downward force of gravity on the skydiver

Explanation: I got it correct on my test on edge

The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.

The statement that best applies Newton’s laws of motion to explain the skydiver’s motion is that an upward force balances the downward force of gravity on the skydiver. Newton's 3rd law often applies to skydiving.

When gravity is not acting upon the skydivers they would continue moving in the direction the vehicle they jumped from was moving. If no air resistance takes place, then the skydivers would still accelerating at 9.8 m/s until they hit the ground.

The skydiver after leaving the aircraft will accelerates downwards due to the force of gravity usually as there is no air resistance acting in the upwards direction, and there is a resultant force acting downwards, the skydiver will accelerates towards the ground.

Therefore, The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.

Learn more about skydiver on:

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Answer; 4.4cm

Explanation: There is a ruler upon which the cylinder start from 1.4cm and reaches 10.2cm

distance traveled =10.2-1.4=8.8

since this cylinder is small so the linear distance can be approximately taked as rotational distance(as in case of point charge) so

2x2πxr =8.8

so the circumference will be 2πr=4.4cm

Answer:

1.7 BTU

Explanation:

q = mCΔT

q = (25 g) (0.9 J/g/°C) (100°C − 20°C)

q = 1800 J

q = 1800 J × (1 BTU / 1055 J)

q = 1.7 BTU

Explanation:

Given that,

Mass of a man, m = 75 kg

(1) We need to find the reading of the weighing machine when the lift is moving upwards with an acceleration of 2 m/s². When the lift is moving upward, reading of the weighing machine is given by :

R = m(g+a)

R = 75 (9.8+2)

R = 885 N

(2) When the lift is moving downwards with a constant velocity of 1.5m/s. It means that the lift is at rest. So, the reading is :

R = mg

R = 75 (9.8)

R = 735 N

(3) When the lift is moving downwards with an acceleration of 2.5 m/s². In this case,

R = m(g-a)

R = 75 (9.8-2.5)

R = 547.5 N

Hence, this is the required solution.

Answer:

speed=330m/s

Explanation:

the speed of wave is given as

speed(meter per second) =frequency(hertz) * wavelength(meters)

so using the above formula we substitute the figures given in the question in the formula we get

speed = 0.4*825

speed =330m/s

note m/s is the si unit for speed which is read as meter per second

therefore speed =330m/s

Answer:

Average acceleration = Displacement / (time)^2

Explanation:

The unit for acceleration is

[tex]m {s}^{ - 2} [/tex]

Displacement = m

Time = s

Hence the units of displacement and time should be manipulated to get the unit of acceleration.

You can't. You can only find average velocity.

But if you also know that initial velocity is zero ... the object started from rest ... then

Avg acceleration =

2 x displacement / time-squared

Answer:

17) a) 30 kg·m/s

b) 30 kg·m/s

c) 0.3 m/s.

18) 2.4 m/s

19) 360,000 N

The different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact

Explanation:

17) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the astronaut = 100 kg

v₁ = The initial velocity of the astronaut = 0 m/s

m₂ = The mass of the equipment box = 2.5 kg

v₂ = The initial velocity of the equipment box = 0 m/s

v₁' = The final velocity of the astronaut

v₂' = The final velocity of the equipment box = 12 m/s

The final momentum of the equipment box = Mass of the equipment box × Final velocity

a) The final momentum of the equipment box = 2.5 kg × 12 m/s = 30 kg·m/s

b) Given that the box and the astronaut will move in opposite directions, we have;

m₁·0 + m₂·0 = -m₁·v₁' + m₂·v₂'

m₁·v₁' = m₂·v₂'

Therefore, the momentum of the astronaut will be equal to the momentum of the equipment box = 30 kg·m/s

c)  The velocity of the astronaut is given by th following relation;

100×0 + 2.5×0 = -100×v₁' + 2.5×12

100×v₁' = 2.5×12

v₁' = 2.5×12/100 = 30/100 = 0.3 m/s

The final velocity of the astronaut = 0.3 m/s.

18) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the railway truck= 4000 kg

v₁ = The initial velocity of the railway truck= 8 m/s

m₂ = The mass of the stationary truck = 6000 kg

v₂ = The initial velocity of the stationary truck = 0 m/s

v₁' = The velocity of the two trucks immediately after collision

Therefore, we have;

4000 kg × 6 m/s + 6000 × 0 = (6000 + 4000) × v₁' = 10,000·v₁'

24,000 kg·m/s = 10,000·v₁'

v₁' = 24,000/10,000 = 2.4 m/s

The velocity of the two trucks immediately after collision is = 2.4 m/s

19) The change in kinetic energy of the car due to the collision = 1/2·m·(v₂² - v₁²)

The initial velocity of the car, v₁ = 12 m/s

The final velocity, v₂ = 0 m/s

The mass of the car, m= 600 kg

The time in which the car is brought to rest = 2 seconds

Initial time at point of collision, t₁ = 0 s

Time after collision, t₂ = 0.02 s

By Newton's second law of motion, we have

The force F acting on the car = Rate of change in momentum produced by the force

F = m × dv/dt

Force  = m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.02 - 0) = -360,000 kg·m/s²

The force acting on the car  is equal and opposite to the force of the car =  360,000 N

b) For the different make of the car, we have;

m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.25 - 0) = -28,800 kg·m/s². = -28,800 N

Therefore, the different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact.

Answer:

the car uses teleportation, to zip to one side of the photo, to the other

Explanation:

Answer:

C. The number of shells increases from top to bottom

Explanation:

There are some trends about the periodic table, one of them is that in the vertical columns of periodic table, the number of shells increases from top to bottom.

From top to bottom in a periodic table, the number of electrons increases, thus more number of shells are needed to fill these electrons and the number of shells increases or we can say the atomic radius increases from top to bottom.

Hence, the correct option is "C".

Answer:

Both are the same.

Explanation:

[tex]pressure= \frac{force}{area} = \frac{f}{a} = \frac{n}{m {}^{2} } [/tex]

The SI unit was named after Bláise Pascal to honor him.

Hope this helps ;) ❤❤❤

This question is incomplete; here is the complete question:

Marco is conducting an experiment. He knows the wave that he is working with has a wavelength of 32.4 cm. If he measures the frequency as 3 hertz, which statement about the wave is accurate?

A. The wave has traveled 32.4 cm in 3 seconds.

B. The wave has traveled 32.4 cm in 9 seconds.

C. The wave has traveled 97.2 cm in 3 seconds.

D. The wave has traveled 97.2 cm in 1 second.

The answer to this question is D. The wave has traveled 97.2 cm in 1 second.

Explanation:

The frequency of a wave, which is in this case 3 hertz, represents the number of waves that go through a point during 1 second. According to this, if the frequency of the wave is 3 hertz this means in 1 second there were 3 waves. Moreover, if you multiply the wavelength (32.4cm) by the frequency (3) you will know the distance the wave traveled in 1 second: 32.4 x 3 =  97.2 cm. This makes option D the correct one as the distance in 1 second was 97.2 cm.

Answer:Is D!

Explanation:TEAT(Sorry) -_-*

Answer:

Using

1/2mv^2 = work done by friction

work done = force x distance

lets call the force 3 N

lets call v = 3 m/s

lets call mass = 2 kg

0.5 x 2 x 3^2 = 9 J

9/3N = 3 m/s

now times 3 m/s by square root of 2 of which is 1.4142

3 x 1.4142= 4.2426 m/s

0.5 x 2 x 4.2426^2 = 18

18/2N = 9 m

Explanation:

Hello there!!!

You just need to use simple formula for force and momentum,

F= m.a

and momentum (p)= m.v

where m= mass

v= velocity.

a= acceleration .

And the solutions are in pictures.

Hope it helps..

Answer:

the focal length of the mirror is :  [tex]f=-2.5\,\,cm[/tex]

Explanation:

Use the formula for the formation of image using a divergent mirror and recalling that the image (s') that this mirror formed is virtual, so it is entered as a negative number in the formula. Use the object position (s) as 10, the image position (s') as -2, and derive the value of the focal length:

[tex]\frac{1}{s} +\frac{1}{s'}=\frac{1}{f}\\\frac{1}{10} +\frac{1}{-2}=\frac{1}{f}\\\frac{1}{10} -\frac{1}{2}=\frac{1}{f}\\\frac{10\,f}{10} -\frac{10\,f}{2}=\frac{10\,f}{f}\\f-5\,f=10\\-4\,f=10\\f=-2.5\,\,cm[/tex]

Answer:

Positive

Explanation:

In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive

Answer:

Option B. 2 A.

Explanation:

The following data were obtained from the question:

Resistance 1 (R1) = 1 Ω

Resistance 2 (R2) = 2 Ω

Resistance 3 (R3) = 3 Ω

Potential difference (V) = 12 V.

Current through the 3 Ω (I3) =?

Next, we shall determine the total resistance of the circuit.

This can be obtained as follow:

Resistance 1 (R1) = 1 Ω

Resistance 2 (R2) = 2 Ω

Resistance 3 (R3) = 3 Ω

Total resistance (R) =.?

R = R1 + R2 + R3

R = 1 + 2 + 3

R = 6 Ω

Next, we shall determine the current flowing in the circuit.

This can be obtained as follow:

From ohm's law,

Voltage (V) = current (I) x resistance (R)

V = IR

Potential difference (V) = 12 V.

Resistance (R) = 6 Ω

Current (I) =?

V = IR

12 = I x 6

Divide both side by 6

I = 12/6

I = 2 A.

Since the circuit is in series connection, therefore, the same current will flow through each resistor.

Therefore, the current through the the 3 Ω load is 2 A.

Answer:

Matter can be identified through its properties. One clue to helps us identify matter is magnetism. Magnetism is the ability of a material to be attracted by a magnet. Only certain materials are attracted to magnets, like iron, nickel, and cobalt.

Explanation:

we can identify matter by:  physical properties  and

chemical properties

Answer:

C. Meter

Explanation:

The International System of Unit (SI) is gotten from the french word Systeme international is a modern form of metric measurement. It is the system of measurement that is universally accepted. It is from this SI units that all other system of units are derived. There are seven basic SI units which are:

1) Length in Meter (m)

2) Time in Seconds (s)

3) Amount of Substance in mole (m)

4) Electric current in ampere (A)

5) Temperature in kelvin (k)

6) Luminous intensity in candela (cd)

7) Mass in kilogram (kg)

Answer:

integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive

Explanation:

and this is biology not physics

Explanation:

a clinical thermometer is a thermometer used to measure human body temperature. mostade in the 20th century are mercury-in-glass thermometer. they ate accurate and sensitive having a narrow place where the mercury level rises very fast. a kink in the tube stops the mercury level from falling on its own.

hope it helps you

Answer:

Space in the astronomy and cosmology space is 3 dimensional region and earth atmosphere end is called space.

Explanation:

Space is the everything of the top earth atmosphere moon, starts, milky way, black hole and GPS satellites an distant,space also called between stars,moon,planet.

Space is all the extends far in all directions, space is finite unbound space surface of the earth has finite are no beginning or not end.

Space contains there are three dimensions is called 3 D space,an space is to refer an interval during signal transmitted also used by the character, bytes, words and octets in  digital signal.

space is that term can refer to various in science, communications and mathematics,and maintain orbits for responsible time, space is usually to begin at the lowest attitude satellites  can maintain orbits.

space coordinates are uniquely define the location of any particular point  and that continuum requires more than coordinates,and the number of dimensions and conventional space or digital communications during the  signal represents logic is 0 words in a digital signal.  

Answer:

d

Explanation:

a and b: it vibrates in both the difference is whether you hear the sound or not the lack or presence of molecules does not hinder the timing fork from vibrating but can hinder you from hearing since sound is a mechanical wave therefore require a medium bringing us to (c) these vibrations are transmitted because there is presence of a medium i.e air molecules so sound can be heard

but in (c) it is true since the vibrations are created but are not transmitted to your ears due to lack of a medium

Answer:

The position of the particle is 6m

The velocity of the particle is 16 m/s in negative direction

The acceleration of the object is -40 m/s²

Explanation:

Given;

motion of the particle along a straight line as x = 6 + 4t² - t⁴

The position of the object when t = 2s

x = 6 + 4(2)² - (2)⁴

x = 6 + 16 - 16

x = 6m

The velocity of the object when t = 2s

Velocity = dx/dt

dx/dt = 8t - 4t³

when t = 2s

Velocity = 8(2) - 4(2)³

Velocity = 16 - 32

Velocity = -16m/s

Velocity = 16 m/s (in negative direction)

The acceleration of the object when t = 2s

Acceleration = d²x/dt² = 8 - 12t²

Acceleration = 8 - 12 (2)²

Acceleration =  -40 m/s²

Answer:

D. 288 psig

Explanation:

The storage cylinder of recovered R-404A is a mixture of R-125, R-143 and R-134. The refrigeration sector has low temperatures for installation. The pressure of cylinder at 80 F will be 288 psig. The pure refrigerants have inside a container have saturation temperature which is equal to ambient temperature.

Answer:

Option D (Electricity can flow through it under special conditions ) seems to be the correct choice.

Explanation:

Other options that are provided are not related to the given theory. So that the above would be the correct choice.

Statement "Lack free electrons that can move to other atoms " describe semi-conductor.

Learn  more about the Semiconductor here:

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Answer:

Protons

Neutrons

Electrons.

Protons + charge(positively charged)

Neurons no charge.

Electrons - ( negatively charged).

Explanation:

Atom is the smallest unit of a matter that constitutes chemical elements.

It is composed of three particles which are protons,neutrons and electrons.

Protons is positively charged,neuron has no charge and electrons is negatively charged.

Proton and neuron are found in the nucleus while electron is found outside the neuron.

Answer:

Vibrations from neighboring atoms

Explanation:

When a rod is heated, the thermal energy transferred to the molecules of the rod causes them to vibrate faster. As the molecules near the heat source vibrate faster, they eventually transfer their excess energy to neighbouring molecules which also begin to vibrate faster. This continues until heat is distributed throughout the length of the rod.

The process described above is known as heat transfer by conduction.