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3 years ago

Please help!!

Physics

1 answer:

HACTEHA [7]3 years ago

7 0

Answer:

An element is a pure substance that contains only one type of atom. TRUE. 2. ... FALSE, they are all carbon atoms. 7. The smallest unit of matter is an atom. TRUE. 8. When an ... TRUE. 10. Most of the mass of an atom is found in the electron layers. FALSE. 11. The nucleus of an atom contains protons and neutrons. TRUE ...

Explanation:

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The depth of a pond is 1.5m. Calculate the pressure caused by the water at the bottom of the pond ??

zepelin [54]

Answer:

Area=1.5(1.5)=2.25m^2

Force of gravity=10N

\begin{gathered}\\ \sf\longmapsto Pressure=\dfrac{Force}{Area}\end{gathered}

⟼Pressure=

Area

Force

\begin{gathered}\\ \sf\longmapsto Pressure=\dfrac{10}{2.25}\end{gathered}

⟼Pressure=

2.25

\begin{gathered}\\ \sf\longmapsto Pressure=4.4Pa\end{gathered}

⟼Pressure=4.4Pa

5 0

3 years ago

Can a goalkeeper at his goal kick a soccer ball into the opponent’s goal without the ball touching the ground? The distance will

zmey [24]

The goalkeeper at his goal cannot kick a soccer ball into the opponent’s goal without the ball touching the ground

Explanation:

Consider the vertical motion of ball,

We have equation of motion v = u + at

Initial velocity, u = u sin θ

Final velocity, v = 0 m/s

Acceleration = -g

Substituting

v = u + at

0 = u sin θ - g t

$t=\frac{usin\theta }{g}$

This is the time of flight.

Consider the horizontal motion of ball,

Initial velocity, u = u cos θ

Acceleration, a =0 m/s²

Time, $t=\frac{usin\theta }{g}$

Substituting

s = ut + 0.5 at²

$s=ucos\theta \times \frac{usin\theta }{g}+0.5\times 0\times (\frac{usin\theta }{g})^2\\\\s=\frac{u^2sin\theta cos\theta}{g}\\\\s=\frac{u^2sin2\theta}{2g}$

This is the range.

In this problem

u = 30 m/s

g = 9.81 m/s²

θ = 45° - For maximum range

Substituting

$s=\frac{30^2\times sin(2\times 45)}{2\times 9.81}=45.87m$

Maximum horizontal distance traveled by ball without touching ground is 45.87 m, which is less than 95 m.

So the goalkeeper at his goal cannot kick a soccer ball into the opponent’s goal without the ball touching the ground

6 0

3 years ago

A 500 N weight sits on the small piston of a hydraulic machine. The small piston has area 2.0 cm2. If the large piston has area

Ghella [55]

Answer:

d. 10000N

Explanation:

When a force ( $F_1$ ) is exerted on the smaller area piston ( $A_1$ ), the pressure that originates therein is transmitted to the larger area piston( $A_2$ ). According to Pascal's principle the pressure on the smallest piston ( $P_1=\frac{F_1}{A_1}$ ) will be equal to the pressure on the largest piston ( $P_2=\frac{F_2}{A_2}$ ):