what are the factor that affect the efficiency of a pulley​

Answer:

0.25 second  

Explanation:

Given :

Velocity, v = 10 m/s

The height,

[tex]$ h = \frac{v^2}{2g} $[/tex]

[tex]$ h = \frac{10^2}{2\times 9.8} $[/tex]

   = 5 m

Therefore the time at which both the bodies meet is

[tex]$ t = \frac{h}{v+v} $[/tex]

[tex]$ t = \frac{5}{10+10} $[/tex]

[tex]$ t = \frac{5}{20} = 0.25$[/tex]

So, time taken is 0.25 seconds

Answer:

Electrons move in specific orbits in the modern model.

Explanation:

I'm still learning so, and D is not the answer.

The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.

New theories usually don’t start “from scratch.” For example, the modern model of the atom is the result of new information added to the cloud model.

What is the main difference between the cloud model of the atom and the modern model?

The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.

You can learn more about atomic models here: https://brainly.com/question/1596638

Answer:

because we more see th online gaming and not eat food and playing that game all the time so it effect the health

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Click at the above pic and the ans will appear.

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Answer:

Explanation:

In this problem, we are expected to solve/find the total distance traveled and also the displacement of the ball.

given that the initial height is 1.5m and was thrown to a height of 5m

the total distance covered when the ball falls to the ground

Note (see attached a rough sketch for the pictorial explanation)

1.  The distance for A to B= 3.5 m

2. The distance from B to A= 3.5 m

3. The distance fro A to C= 1.5 m

the total distance is 3.5+3.5+1.5= 8.5m  

the displacement is simply the difference  between the final position and the initial position

displacent= 5-1.5= 3.5m

Answer:

50m/s2^

Explanation:

We know , by newton's law of motion .

F=ma

a=f/m

a=25/0.5

a=50m/s2^

Therefore , the acceleration of a softball is  .

Answer:

7 m/s²

Explanation: Force = Mass x acceleration  

Also note that 1 N = 1 kg.m/s²

a=F/ m

a= 35 N/ 5 kg = 35 kg.m/ s²  ÷  kg                 Aside:( so you cross out the kg)

a= 7 m/s²

Answer:

Explanation:

The recommendations that need to be urgently addressed by the workshop and it's employees are

1) Training of all employees (particularly the tool operators) on the safe and proper use of all tools used in the course of the carpentry work.

2) Training of all employees in health, safety and environment (HSE). This training will help them appreciate the importance of always wearing personal protective equipment (PPE) when at the workshop or during the course of a work (because if the apprentice was putting on an engineer's helmet, he could have been safe).

3) Employees who fail to adhere strictly to the use of PPE should be sanctioned or even dismissed from the workplace

Answer:

B expansion  

Explanation:

In a cloud of gas and dust known as the solar nebula, the Sun and the planets jointly created 4.6 billion years ago. The solar nebula presumably collapsed as a result of a shock wave from a nearby supernova explosion. Thus, option A is correct.

A nearby supernova explosion's shock wave is most likely what caused the solar nebula to collapse.The planets formed in a thin disk around the Sun, which formed in the centre of the solar system. Moons began to form similarly around the gas giant planets.

Every speck of stuff in the solar system was once a massive nebula, or floating interstellar cloud, before it was shaped into a tidy collection of planets.

Therefore, a shock wave from an exploding supernova triggered dust particles to be drawn together to form a dense spherical cloud.

Learn more about nebula here:

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Answer:

46m

Explanation:

Given the following :

Initial Velocity (u) = 60

Angle(θ) = 30°

Maximum height it will reach?

The maximum height if a projection is calculated using the formula :

H = u²sin²θ / 2g

Where H = maximum height, g = acceleration due to gravity = 9.8m/s²

H = (60²sin × 0. 5²) / 2(9.8)

H = 900 / 19.6

H = 45.918m

H = 46m

Answer:

Choice A. It has chloroplast

Plants have chloroplast and animals dont

Explanation:

It having chloroplasts is the observation which would support the claim that it is a plant cell rather than an animal cell.

This is as organelle which produces the pigment known as chlorophyll and it is used during the process of photosynthesis.

Plants are known as primary producers and are involved in this process which is why option B was chosen.

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Answer:

4.4x10^-32m

Explanation:

Using

Wavelength = hc/E

= 6.63*10^-34 * 3x10^8/ 4.5 x10^ 6ev

= 4.4*10^-32m

Yes a relativistic approach is used because the particle moves at the speed of light

Answer:

true

Explanation:

i did the test its right

Answer:

true

mark mine as brainiest, i could use the points

Answer: the answers are

(2)Both involve the formation of solid particles from nebular materials

And

(4)Both involve the trapping of gases and the clumping of masses of matter

Explanation:

Answer : The correct degree of precision is 272.94 g.

Explanation :

Precision : It is defined as the closeness of two or more measurements to each other.

For Example: If you weigh a given substance five times and you get 2.7 kg each time. Then the measurement is said to be precise.

Level of precision is determined by the maximum number of decimal places.

In the given figure, the value of mass of object is 280 g. From the given options we conclude that the 272.94 g is more close to 280 g and has maximum number of decimal places. So, 272.94 g measurement is said to be precise.

Therefore, the correct degree of precision is 272.94 g.

Answer: Well their are many Miles, inches, kilometres, meters, cementers, and so on.

hope it helps you bye

Centimetre, Meter, & Kilometre

Answer:

Q1: 3.2km

Q2: 4.8K

Explanation:

Q1:

So db is the distance of bird, and dr is the distance of runner

db = 2vr  and the distance of bird is going to be 2 times greater than the runner.

formulas: db = 2vr & db = 2dr

Insert it in x = [tex]\frac{2}{3}[/tex]L

[tex]\frac{2}{3}[/tex](2.4km) = 1.6km

Now we use formula db = 2dr

Q2:

Formulas: Vr = L /Δt & Vb = db/Δt

(Km cancel each other)

(hr cancel each other)

Hope it helps you :)

Answer: a) B = 6811N

              b) m = 603.2kg

              c) 86.8%

Explanation: Buoyant force is a force a fluid exerts on a submerged object.

It can be calculated as:

[tex]B=\rho_{fluid}.V_{obj}.g[/tex]

where:

[tex]\rho_{fluid}[/tex] is density of the fluid the object is in;

[tex]V_{obj}[/tex] is volume of the object;

g is acceleration due to gravity, is constant and equals 9.8m/s²

a) For the hollow plastic sphere, density of water is 1000kg/m³:

[tex]B=10^{3}.0.695.9.8[/tex]

B = 6811N

b) Anchored to the bottom, the forces acting on the sphere are Buoyant, Tension and Force due to gravity:

B = T + [tex]F_{g}[/tex]

B = T + mg

mg = B - T

[tex]m=\frac{B - T}{g}[/tex]

Calculating:

[tex]m=\frac{6811 - 900}{9.8}[/tex]

m = 603.2kg

c) When the shpere comes to rest on the surface of the water, there are only buoyant and gravity acting on it:

B = m.g

[tex]\rho_{w}.V_{sub}.g=m.g[/tex]

[tex]V_{sub}=\frac{m}{\rho_{w}}[/tex]

[tex]V_{sub}=\frac{603.2}{1000}[/tex]

[tex]V_{sub}[/tex] = 0.6032m³

Fraction of the submerged volume is:

[tex]\frac{V_{sub}}{V_{obj}}[/tex] = [tex]\frac{0.6932}{0.695}[/tex] = 0.868

Explanation:

She walked 20 feet in the first 25 seconds.  Then she stayed at the 20 foot position for 5 seconds.  Then she walked another 20 feet in 25 seconds.  See attached graph.

Answer:

1) 3 applications of pressure in daily life are :-

● The area of sharp edge of knife, scissor or handsaws are much less then blunt edge. So, for same total force pressure is more for sharp edges than the blunt one. Hence sharp knife, scissors etc, cuts easily than a blunt one.

●Broad handles in bags and suitcases are provided for the comfort. Broad handles have large area. So, the pressure exerted on hands and shoulders would be small while carrying the bags and the suitcases.

●Trucks carrying heavy loads have more than four tyres. More tyres in case of trucks increase the area of contact with the road. This results in reduced pressure on the tyres.

2) Area of the surface which is on ground = 1.5×1

= 1.5m^2

Mass of the block = 300kg

Force applied by the block = Mass × g = 300×10

= 3000N (where g = acceleration due to gravity )

Pressure = Force applied / Area of the surface

= 3000N / 1.5m^2

= 2000 Pa

3)

a) The above experiment signifies that more the area of the surface of an object , less the pressure an object applies.

b) B exerts the minimum pressure because the area of its surface to ground is greater than others & as it has more area of surface , it exerts less pressure. ( area is inversely proportional to pressure )

c) D exerts the maximum pressure because the area of its surface to ground is lesser than others & as it has less area of surface , it exerts more pressure. ( area is inversely proportional to pressure )

d) It depend upon the way an object is kept on ground. If an object is kept in such a way dat the area of the surface to the ground is more , then pressure will be least exerted .If an object is kept in such a way dat the area of the surface to the ground is less, then pressure will be exerted more .

e) Do it yourself . only i will suggest that make the tip of the cone ( which is to the ground ) more narrower.

Explanation:

Answer:

The field will remain the same

Explanation:

This is because electric field given as

E1= kq1/r²

And that of second charge

E² = kq2/r²

Is not affected by the size of the second charge q2

Answer:

they are membrane proteins

Answer:

1. 180 m

2. 1.5 miles/hour

3. 0 m/s

Explanation:

The complete question is

A dog runs 300 m North and sees the dog catcher and runs 120 m south Whats the dogs displacement.

A jogger runs north for 3.0 miles. If this took 2.0 hours, what is the jogger’s average velocity in miles per hour?

The same jogger runs 3.0 miles on the track, starting and finishing his run after completing exactly 12 laps around the track. What is his average velocity?

1. Displacement is how far the dog moves from the original starting point.

If the dog runs 300 m north, and then 120 m south, then the displacement from the starting point will be

displacement = 300 - 120 = 180 m

2. Displacement of the jogger = 3 miles

Time taken by the jogger = 2 hours

velocity of the jogger = ?

Velocity is = displacement/time

velocity = 3/2 = 1.5 miles/hour

3. velocity = displacement/time

if the jogger completes exactly 12 laps around the track, then the jogger will return to the starting point. This means that the jogger's displacement from the starting point is 0 miles

Jogger's velocity will therefore be = 0 m/s

Answer:

b. Research projects for a specific cause

Explanation:

Research funded by private foundations are usually for a specific cause. These type of research are usually properly scrutinized, and must have a high probability of success. Most of these projects may not be to benefit the consumers, but are usually done with a special purpose in mind.

dissolve salt in water then pour the liquid away from the sand and then evaporate the water to recover the salt

Explanation:

4.2 converted to grams equal 119.067997125

Answer:13.6

Explanation:

Answer:

48 m

Explanation:

Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2.

The eastbound train

First convert km/h to m/s

(97 × 1000)/3600

97000/3600

26.944444 m/s

As the train is decelerating, final velocity V = 0 and acceleration a will be negative. Using third equation of motion

V^2 = U^2 - 2as

O = 26.944^2 - 2 × 3.5 S

726 = 7S

S = 726/7

S1 = 103.7 m

The westbound train

Convert km/h to m/s

(127×1000)/3600

127000/3600

35.2778 m/s

Using third equation of motion

V^2 = U^2 - 2as

0 = 35.2778^2 - 2 × 4.2 × S

1244.52 = 8.4S

S = 1244.52/8.4

S2 = 148.2 m

S1 + S2 = 103.7 + 148.2 = 251.86

The distance between them once they stop will be

300 - 251.86 = 48.14 m

Therefore, the distance between them once they stop is 48 metres approximately.

=> 1200 000 mg

We know that,

1 kg = 1000 g

1 g = 1000 gm

then,

1.2kg = 1.2 × 1000 g = 1200 g

1200 g = 1200 × 1000 mg

Answer:

1 and 4

Explanation:

Answer:

3.99*10^-3N/C

Explanation:

Using

Ep= kq/r²

Where r = 0.6mm = 0.6*10^-3m

K= 8.9*10^9 and q= 1.6*10^-19

So = 8.9*10^9 * 1.6*10^-19/0.6*10^-3)²

= 3.99*10^-3N/C

Answer:

A base on scientific event

Explanation:

theories can changeD

they dont explain unusual phenomenaB

Nothing is personal in scienceC