All categories

4 years ago

By applying a force of 55 N, a pulley system can lift a box with a mass of 20.0 kg. What

Physics

1 answer:

Gnesinka [82]4 years ago

7 0

The mechanical advantage of the pulley is 3.56

Explanation:

The Mechanical Advantage (MA) of a pulley system is given by

$MA=\frac{Load}{Effort}$

where

Load is the weight of the object lifted

Effort is the force applied in input

For the pulley in this problem, we have:

Effort = 55 N

While the load is the weight of the box of mass m = 20.0 kg:

$Load = mg = (20.0 kg)(9.8 m/s^2)=196 N$

Substittuing, we find the MA of the pulley:

$MA=\frac{196}{55}=3.56$

#LearnwithBrainly

You might be interested in

A 75-kg human footprint is 0.05 m when the human is wearing boots. Suppose you want to walk on snow surfce that can at most supp

Sholpan [36]

Answer:

area is 0.245 m²

Explanation:

The equation for pressure is

P = F / A

Where P is the pressure, F the force and A the area where the force is applied.

With the data we can calculate the pressure applied by the feet on the human on the floor

P1 = W / A = mg / A

P1 = 75 9.8 / 0.05

P1 = 14700 Pa

Now they tell us that the maxi maque pressure supports the snow is 3 kPa = 3000 Pa, the way to decrease the pressure is to increase the area on which force is applied.

P2 = F / A2

In this case we will calculate the minimum area, so we use the maximum pressure that supports the snow (P2 = 3000 Pa) and the force remains the weight of man

A2 = F / P2

A2= mg / P2

A2 = 75 9.8 / 3000

A2 = 0.245 m²

6 0

3 years ago

Which of the following is not an example of a molecule? A.H2O2 B.NCl3 C.F D.O3

lara [203]

I believe the answer is F. This is because, F stands for Fluorine, which is an element and consists of one atom. A molecule consists of TWO OR MORE atoms held together by chemical bonds. F consists of only one atom, which is Fluorine. So the answer is C. Hope helped.

7 0

3 years ago

Read 2 more answers

The rate at which heat enters an air conditioned building is often roughly proportional to the difference in temperature between

erma4kov [3.2K]

Answer:

Considering first question

Generally the coefficient of performance of the air condition is mathematically represented as

$COP = \frac{T_i}{T_o - T_i}$

Here $T_i$ is the inside temperature

while $T_o$ is the outside temperature

What this coefficient of performance represent is the amount of heat the air condition can remove with 1 unit of electricity

So it implies that the air condition removes $\frac{T_i}{T_o - T_i}$ heat with 1 unit of electricity

Now from the question we are told that the rate at which heat enters an air conditioned building is often roughly proportional to the difference in temperature between inside and outside. This can be mathematically represented as

$Q \ \alpha \ (T_o - T_i)$

=> $Q= k (T_o - T_i)$

Here k is the constant of proportionality

since 1 unit of electricity removes $\frac{T_i}{T_o - T_i}$ amount of heat

E unit of electricity will remove $Q= k (T_o - T_i)$

$E = \frac{k(T_o - T_i)}{\frac{T_i}{ T_h - T_i} }$

=> $E = \frac{k}{T_i} (T_o - T_i)^2$

given that $\frac{k}{T_i}$ is constant

=> $E \ \alpha \ (T_o - T_i)^2$

From this above equation we see that the electricity required(cost of powering and operating the air conditioner) is approximately proportional to the square of the temperature difference.

Considering the second question

Assuming that $T_i = 30 ^oC$

and $T_o = 40 ^oC$

Hence

$E = K (T_o - T_i)^2$

Here K stand for a constant

$E = K (40 - 30)^2$

=> $E = 100K$

Now if the $T_i = 20 ^oC$

Then

$E = K (40 - 20)^2$

=> $E = 400 \ K$

So from this see that the electricity require (cost of powering and operating the air conditioner)when the inside temperature is low is much higher than the electricity required when the inside temperature is higher

Considering the third question

Now in the case where the heat that enters the building is at a rate proportional to the square-root of the temperature difference between inside and outside

We have that

$Q = k (T_o - T_i )^{\frac{1}{2} }$

$E = \frac{k (T_o - T_i )^{\frac{1}{2} }}{\frac{T_i}{T_o - T_i} }$

=> $E = \frac{k}{T_i} * (T_o - T_i) ^{\frac{3}{2} }$

Assuming $\frac{k}{T_i}$ is a constant

Then

$E \ \alpha \ (T_o - T_i)^{\frac{3}{2} }$

From this above equation we see that the electricity required(cost of powering and operating the air conditioner) is approximately proportional to the square root of the cube of the temperature difference.

4 0

3 years ago

Abdou was explaining to a classmate that graphite is a good lubricant because it is bonded in layers that easily slip over each

lesantik [10]

Answer: The correct image is the one with 5 rows, and 9 hexagons in each row.

Explanation:

Just took the quiz

3 0

3 years ago

Read 2 more answers

What does it mean when the mark on the ramrod disappears into the barrel of the muzzleloader?

bagirrra123 [75]

The firearm is unloaded.

The ramrod establishes whether the firearm is loaded or unloaded. It thrusts the bullet down the barrel. It is marked by wrapping some tape around it ( at the muzzle end ). This is to effectively signal if the muzzleloader is empty or loaded.

8 0

3 years ago