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4 years ago

A roller coaster starts from rest at the top ofan 18m hill.

Physics

1 answer:

Sloan [31]4 years ago

6 0

Answer:

v= 12.522 m/s

Explanation:

Supposing we have to find the velocity of the car

By conserving energy we can say that

Initial potential energy= Final potential energy + Final kinetic energy

$mgh_{initial}=mgh_{final}+0.5mv^2$

also h{initial}=18 m

h_{final}=10 m

therefore,

0.5mv^2=mg(18-10)

$v=\sqrt{16g}$

v= 12.522 m/s

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A package is dropped from a hovering helicopter.

aivan3 [116]

Answer:

The height of the package when it was released was 1102.5 meters

Explanation:

A package is dropped from a hovering helicopter

Dropped means the initial velocity of the package is zero

The package takes 15 seconds to strike the ground

Ignore the air resistance

We need to know the height of the package when it was released

$h=ut+\frac{1}{2}gt^{2}$ , where h is the height of the package

from the ground, u is the initial velocity, g is the acceleration of gravity

and t is the time

u = 0 , t = 15 seconds , g = 9.8 m/s²

$h=(0)(15)+\frac{1}{2}(9.8)(15)^{2}$

$h=0+1102.5$

h = 1102.5 meters

<em>The height of the package when it was released was 1102.5 meters</em>

4 0

3 years ago

Which is the correctly balanced equation for the reaction of rust, Fe2O3, and hydrochloric acid, HCl?

Mariana [72]

Answer: Option (c) is correct answer.

Explanation:

The given reaction equation is as follows.

$Fe_{2}O_{3} + HCl \rightarrow FeCl_{3} + H_{2}O$

The number of atoms on reactant side are as follows.

Fe = 2
O = 3
H = 1
Cl = 1

The number of atoms on product side are as follows.

Fe = 1
O = 1
H = 2
Cl = 3

Therefore, in order to balance the equation we will balance the number of atoms in both reactant and product side.

Since number of Fe atoms in reactant side is 2, therefore, multiply $FeCl_{3}$ by 2 in the product side.

Number of O atoms in reactant side is 3, therefore, multiply $H_{2}O$ by 3 in the product side.

Now, the number of H atoms on product side is 6, therefore, multiply HCl by 6 in the reactant side.

The number of chlorine atoms on both reactant and product side equals 6.

Thus, the equation will become as follows.

$Fe_{2}O_{3} + 6HCl \rightarrow 2FeCl_{3} + 3H_{2}O$

Hence, the equation is balanced.

5 0

4 years ago

Read 2 more answers

What creates more pressure?Check all that apply A.Gas molecules moving more quickly B.More gas molecules C. Going to a higher al

Shkiper50 [21]

It's A.Gas molecules moving more quickly..... hope it helps you dear

7 0

3 years ago

A uniform rod is 2. 0 m long and has mass 15 kg. What is most nearly the rod's mass moment of inertia?

trapecia [35]

The rod's mass moment of inertia is 5kgm².

<h3>Moment of Inertia:</h3>

The "sum of the product of mass" of each particle with the "square of its distance from the axis of rotation" is the formula for the moment of inertia.

The Parallel axis Theorem can be used to compute the moment of inertia about the end of the rod directly or to derive it from the center of mass expression. I = kg m². We can use the equation for I of a cylinder around its end if the thickness is not insignificant.

If we look at the rod we can assume that it is uniform. Therefore the linear density will remain constant and we have;

or = M / L = dm / dl

dm = (M / L) dl

$I = \int\limits^M_0 {r^2} \, dm$