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2 years ago

Hi all, can u please help me in this. I would very appreciate it :)

Physics

1 answer:

andreyandreev [35.5K]2 years ago

7 0

<em><u>Questions And Answers About Air Resistance.</u></em>

Question 1: What is Air resistance?

Answer: Air resistance is a force that is caused by air. The force acts in the opposite direction to an object moving through the air. A lorry with a flat front will experience high air resistance while a sports car with a streamlined shape will experience lower air resistance, allowing the car to go faster.

Question 2: What causes air resistance?

Answer: Air resistance, also known as drag, is a force that is caused by air, the force acts in the opposite direction to an object moving through the air. It is where air particles hit the front of the object slowing it down. The more surface area, the more air particles hit it and the greater the resistance.

Question 3: How can air resistance be overcome?

Answer: Two ways to reduce air resistance are stated: reducing the area in contact with air (by the cyclist ducking down or cycling behind someone else) and by being more streamlined (wearing smoother surfaces or a more streamlined helmet).

Question 4: What happens when air resistance increases?

Answer: As it gains speed, the object's weight stays the same but the air resistance on it increases. There is a resultant force acting downwards. Eventually, the object's weight is balanced by the air resistance. There is no resultant force and the object reaches a steady speed – this is known as the terminal velocity.

<em><u>Questions And Answers About Water Resistance.</u></em>

Question 1: What is Water resistance?

Answer: Water resistance is a type of force that uses friction to slow things down that are moving through water. ... Water resistance occurs because of the particles in the liquid. As an object moves through a liquid, it collides with the particles which cause it to slow down.

Question 2: What causes water resistance?

Answer: Water resistance doesn't have to be just water, however, it can happen to objects moving through any type of fluid. Water-resistance happens because of the particles in water or the fluid. As the object moved through it collides with the particles which try to slow it down.

Question 3: How is water resistance useful?

Answer: Like friction and air resistance, it SLOWS THINGS DOWN, trying to stop them from moving. Water resistance can also be useful at times. When you are swimming and you push against the water with your hands, the water-resistance pushes back and helps you to move forward. This also happens when you use oars to row a boat.

Question 4: Does water-resistant mean waterproof?

Answer: The technical definition of water-resistant is that it's able to resist the penetration of water to a certain degree, but not entirely. Waterproof technically means that it's impermeable to water, no matter how much time it spends in the water.

Hope This Helps...:)

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Why does a child in a wagon seem to fall backward when you give the wagon a sharp pull forward? 15. What force is needed to acc

slavikrds [6]

Answer:

Force, F = 77 N

Explanation:

A child in a wagon seem to fall backward when you give the wagon a sharp pull forward. It is due to Newton's third law of motion. The forward pull on wagon is called action force and the backward force is called reaction force. These two forces are equal in magnitude but they acts in opposite direction.

We need to calculate the force is needed to accelerate a sled. It can be calculated using the formula as :

F = m × a

Where

m = mass = 55 kg

a = acceleration = 1.4 m/s²

$F=55\ kg\times 1.4\ m/s^2$

F = 77 N

So, the force needed to accelerate a sled is 77 N. Hence, this is the required solution.

3 0

3 years ago

In which of the following is positive work done by a person on a suitcase

MrRa [10]

pendajo sMh so stupid

4 0

3 years ago

⚠️ PLEASE HELP ⚠️

Svetllana [295]

Answer:

-79.6

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-81.2

Explanation:

5 0

3 years ago

Read 2 more answers

The intensity I of light varies inversely as the square of the distance D from the source. If the intensity of illumination on a

emmasim [6.3K]

The intensity on a screen 20 ft from the light will be 0.125-foot candles.

<h3>What is the distance?</h3>

Distance is a numerical representation of the length between two objects or locations.

The intensity I of light varies inversely as the square of the distance D from the source;

I∝(1/D²)

The ratio of the intensity of the two cases;

$\rm \frac{I_1}{I_2} =(\frac{D_2}{D_1} )^2\\\\ \rm \frac{2}{I_2} =(\frac{20}{5} )^2\\\\ \frac{2}{I_2} =4^2 \\\\ I_2= \frac{2}{16} \\\\ I_2= 0.125 \ foot-candles$

Hence, the intensity on a screen 20 ft from the light will be 0.125 foot-candles

To learn more about the distance refer to the link;

brainly.com/question/26711747

#SPJ1

6 0

2 years ago

The maximum speed with which you can throw a stone is about 20 m/s. Can you hit a window 45 m away horizontally and 10 m up from

Allushta [10]

Answer:

y = 17 m

Explanation:

For this projectile launch exercise, let's write the equation of position

x = v₀ₓ t

y = $v_{oy}$ t - ½ g t²

let's substitute

45 = v₀ cos θ t

10 = v₀ sin θ t - ½ 9.8 t²

the maximum height the ball can reach where the vertical velocity is zero

v_{y} = v_{oy} - gt

0 = v₀ sin θ - gt

0 = v₀ sin θ - 9.8 t

Let's write our system of equations

45 = v₀ cos θ t

10 = v₀ sin θ t - ½ 9.8 t²

0 = v₀ sin θ - 9.8 t

We have a system of three equations with three unknowns for which it can be solved.

Let's use the last two

v₀ sin θ = 9.8 t

we substitute

10 = (9.8 t) t - ½ 9.8 t2

10 = ½ 9.8 t2

10 = 4.9 t2

t = √ (10 / 4.9)

t = 1,429 s

Now let's use the first equation and the last one

45 = v₀ cos θ t

0 = v₀ sin θ - 9.8 t

9.8 t = v₀ sin θ

45 / t = v₀ cos θ

we divide

9.8t / (45 / t) = tan θ

tan θ = 9.8 t² / 45

θ = tan⁻¹ ( 9.8 t² / 45 )

θ = tan⁻¹ (0.4447)

θ = 24º

Now we can calculate the maximum height

v_y² = $v_{oy}^2$ - 2 g y

vy = 0

y = v_{oy}^2 / 2g

y = (20 sin 24)²/2 9.8

y = 3,376 m

the other angle that gives the same result is

θ‘= 90 - θ

θ' = 90 -24

θ'= 66'

for this angle the maximum height is

y = v_{oy}^2 / 2g

y = (20 sin 66)²/2 9.8

y = 17 m

thisis the correct

6 0

3 years ago