G s w d v b k x s r only for freinds <br> Have a pretty heart

A roller coaster starts from rest at its highest point and then descends on its (frictionless) track. its speed is 40 m/s when i

Alenkinab [10]

Given that,

Initial velocity , Vi = 0

Final velocity , Vf = 40 m/s

Acceleration due to gravity , a = 9.81 m/s²

Distance can be calculated as,

2as = Vf² - Vi²

2 * 9.81 *s = 40² - 0²

s = 81.55 m

For half height, that is, s = 40.77m

Vf= ??

2as = Vf² - Vi²

2 * 9.81 * 40.77 = Vf² - 0²

Vf² = 800

Vf = 28.28 m/s

Therefore, speed of roller coaster when height is half of its starting point will be 28 m/s.

5 0

2 years ago

Ali mixes 20g of Sodium Chloride in 100g of water at 15 Degree °C. Calculate the mass of the solution

Lera25 [3.4K]

Answer:

The mass of the solution is 120 g.

Explanation:

The mass of the solution is given by:

$m_{sol} = m_{1} + m_{2}$

Where:

$m_{sol}$ : is the mass of the solution

$m_{1}$ : is the mass of the solvent

$m_{2}$ : is the mass of the solute

In the solution, the solvent is the majority compound (in mass) and the solute is the minority (in mass), so the solvent is the water and the solute is sodium chloride.

Hence, the mass of the solution is:

$m_{sol} = m_{1} + m_{2} = 100 g + 20 g = 120 g$

I hope it helps you!

7 0

2 years ago

An object dropped from rest from the top of a tall building on planet x falls a distance d(t)18 left parenthesis t right parenth

melamori03 [73]

displacement is given by equation

$d = 18t^2$

now at t = 5 s the position is

$d_1 = 18 *5^2 = 450 m$

similarly position at t = 9 s

$d_2 = 18*9^2 = 1458 m$

so the displacement of object in given interval of time will be

$d = 1458 - 450 = 1008 m$

time interval

$\delta t = 9 - 5 = 4 s$

now the average velocity will be given as

$v = \frac{\delta x}{\delta t}$

$v = \frac{1008}{4} = 252 m/s$

so its average speed is 252 m/s

4 0

2 years ago

According to Bernoulli's equation, the pressure in a fluid will tend to decrease if its velocity increases. Assuming that a wind

Pie

Answer:

The pressure drop predicted by Bernoulli's equation for a wind speed of 5 m/s

= 16.125 Pa

Explanation:

The Bernoulli's equation is essentially a law of conservation of energy.

It describes the change in pressure in relation to the changes in kinetic (velocity changes) and potential (elevation changes) energies.

For this question, we assume that the elevation changes are negligible; so, the Bernoulli's equation is reduced to a pressure change term and a change in kinetic energy term.

We also assume that the initial velocity of wind is 0 m/s.

This calculation is presented in the attached images to this solution.

Using the initial conditions of 0.645 Pa pressure drop and a wind speed of 1 m/s, we first calculate the density of our fluid; air.

The density is obtained to be 1.29 kg/m³.

Then, the second part of the question requires us to calculate the pressure drop for a wind speed of 5 m/s.

We then use the same formula, plugging in all the parameters, to calculate the pressure drop to be 16.125 Pa.

Hope this Helps!!!

7 0

2 years ago

How are electromagnetic waves able to travel without a medium?

vazorg [7]

Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. this means that electromagnetic waves can travel not only trough air and solid materials, but also trough the vacuum of space.

7 0

2 years ago

G s w d v b k x s r only for freinds Have a pretty heart