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2 years ago

7

A ball is thrown vertically upward at 24.0 ms can reach a height of 28.8m ( neglecting air resistance).The speed,in m/s,when it

is halfway to its highest point is (using g= 10 ms ^2)

1 answer:

ICE Princess25 [194]2 years ago

3 0

Answer:

The answer is " $16.79\ \frac{m}{s}$ "

Explanation:

In this question, the halfway indicates the height that is $\frac{28.8}{2}=14.4 \ m$

Using formula:

$v^2=u^2+2as\\\\v^2=24^2+2(-10)(14.4)\\\\$

$v^2=576-288\\\\v^2=288\\\\v=\sqrt{288}\\\\v=16.97 \ \frac{m}{s}$

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A model airplane of mass 0.6 kg is attached to a horizontal string and flies in a horizontal circle of radius 6 m, making 1.6 re

nikitadnepr [17]

Answer:

$speed= 12.15\frac{m}{s}$

Explanation:

In this question we have given

mass of airplane=.6 Kg

Radius of horizontal circle,r=6m

Time taken to complete 1.6 revolution=5s

Therefore time taken to complete 1 revolution, t= $\frac{5}{1.6}$

t=3.1 s

We have to find the speed of airplane

We will first find the distance covered by airplane in tracing one circle which is equal to circumference of circle

We know that

Circumference,d = $2 \pi \times r$

or $d=2\times 3.14 \times 6$

$d=37.68 m$

We know that speed= $\frac{d}{t}$ ............(1)

Put value of d and t in equation 1

speed= $\frac{37.68}{3.1}$

$speed= 12.15\frac{m}{s}$

5 0

3 years ago

Azurite is a mineral that contains 55.1% of copper. How many meter of copper wire with diameter of 0.0113 in can be produced fro

soldier1979 [14.2K]

Answer:

1402.73 m

Explanation:

Mass of Azurite=3.25 lb

Percent of copper in AZurite mineral=55.1%

Diameter of copper wire,d=0.0113 in

Radius of copper wire= $r=\frac{d}{2}=\frac{0.0113}{2}=0.00565 in=\frac{565}{100000}=\frac{565}{100}\times \frac{1}{1000}=5.65\times 10^{-3}in$

$\frac{1}{1000}=10^{-3}$

Density of copper= $\rho=8.96g/cm^3$

1 lb=454 g

3.25 lb= $3.25\times 454=1475.5 g$

Mass of Azurite= $1475.5 g$

Mass of copper= $\frac{55.1}{100}\times 1475.5=813 g$

Density= $\frac{Mass}{volume}$

Using the formula

$8.96=\frac{813}{volume\;of\;copper}$

Volume of copper wire= $\frac{813}{8.96}=90.7cm^3$

Radius of copper wire= $5.65\times 10^{-3}\times 2.54=14.35\times 10^{-3} cm$

1 in=2.54 cm

Volume of copper wire= $\pi r^2 h$

$\pi=3.14$

Using the formula

$90.7=3.14\times (14.35\times 10^{-3})^2\times h$

$h=\frac{90.7}{3.14\times (14.35\times 10^{-3})^2}$

$h=140273 cm$

1 m=100 cm

$h=\frac{140273}{100}=1402.73 m$

Hence, the length of copper wire required=1402.73 m

7 0

3 years ago

A truck is carrying a refrigerator as shown in the figure. The height of the refrigerator is 158.0 cm, the width is 60.0 cm. The

kirza4 [7]

In order for the refrigerator not to tip over, the maximum acceleration of 1.86 m/s² must not be exceeded.

<h3>What is acceleration?</h3>

The term acceleration has to do with the rate at which velocity changes with time.

We have to take the moments at the tipping point of rotation as follows;

Clockwise moment = Anticlockwise moment

Hence;

F₂ * 1.58 m = F₁ * 0.67 m

The weight at half the width= 30 cm or 0.3 m

Height of refrigerator = 158 cm 0r 1.58 cm

Then;

m * a * 1.58 = m * 9.81 * 0.30

a = 1.86 m/s²

In order for the refrigerator not to tip over, the maximum acceleration of 1.86 m/s² must not be exceeded.

Learn more about acceleration: brainly.com/question/14344386

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5 0

2 years ago

A ball rolls down a hill and hits a box. The momentum of the ball decreases. Which happens to the momentum?

Nezavi [6.7K]

First let us examine our options. For B, the law of inertia state that an object will keep on moving unless acted upon an external force. And I am thinking this is not the appropriate answer here. Also for C momentum and mass are not the same. Momentum is energy. Momentum cannot be converted to mass. A is the answer since momentum. When the ball hits the box, the box will move and decreases the velocity of the rock. Here momentum is transferred. <span />

8 0

3 years ago

A 65-kg swimmer pushes on the pool wall and accelerates at 6 m/s^2. The friction experienced by the swimmer is 100 N. How many N

DochEvi [55]

Answer:

490N

Explanation:

According Newton's second law!

\sum Force = mass × acceleration

Fm - Ff = ma

Fm is the moving force

Ff s the frictional force = 100N

mass = 65kg

acceleration = 6m/s²

Required

Moving force Fm

Substitute the given force into thr expression and get Fm

Fm -100 = 65(6)

Fm -100 = 390

Fm = 390+100

Fm = 490N

Hence the force that will cause two cart to move is 490N

3 0

2 years ago