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2 years ago

9

Ramu,the gardener,is trying to pull out weeds. however,he has to apply great force.why do you think he has to apply to much forc

e?

1 answer:

jasenka [17]2 years ago

4 0

Answer:

Roots are basically hooked into the ground?

Explanation:

Maybe you could comment here the choices if it's multiple choice.

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Which compound is most likely a covalent compound?<br> Melting Boiling

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Answer:

compound A

Explanation:

because covalent compounds can't conduct electricity and because they also have low boiling points

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3 years ago

How much energy is required to change a 44 g

zlopas [31]

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Ang answer units of J heat of fusion is 3.33 x 105

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3 years ago

What happens in a tug of war if the net forces are balanced and why?

FinnZ [79.3K]

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Balanced forces are responsible for unchanging motion. Balanced forces are forces where the effect of one force is cancelled out by another. A tug of war, where each team is pulling equally on the rope, is an example of balanced forces. The forces exerted on the rope are equal in size and opposite in direction.

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3 years ago

The diagram shows a screwdriver being used as a lever to open a tin

Musya8 [376]

Answer:

(a) Most reactive ${}$ Metal B

${}$ Metal D

${}$ Metal A

Least reactive ${}$ Metal C

(b) (i) Bubbles should form very slowly

(ii) No reaction takes place

Explanation:

(a) The given metals arranged in their order of reactivity are;

Most reactive ${}$ Metal B

${}$ Metal D

${}$ Metal A

Least reactive ${}$ Metal C

The other of reactivity is based on the nature of their reactivity of the metals in air

(b) (i) Based on the reactivity of the metals in air, whereby metal A reacts very slowly and an oxide is formed, we have that, based on the reactivity of the metal A, when mixed with dilute hydrochloric acid, bubbles should form very slowly

(ii) Similarly, given that metal C is unreactive, we have that when small pieces of metal C are added to dilute hydrochloric acid, no reaction takes place.

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3 years ago

A bug is 12 cm from the center of a turntable that is rotating with a frequency of 45 rev/min . What minimum coefficient frictio

Agata [3.3K]

Answer:

The minimum coefficient of friction is 0.27.

Explanation:

To solve this problem, start with identifying the forces at play here. First, the bug staying on the rotating turntable will be subject to the centripetal force constantly acting toward the center of the turntable (in absence of which the bug would leave the turntable in a straight line). Second, there is the force of friction due to which the bug can stick to the table. The friction force acts as an intermediary to enable the centripetal acceleration to happen.

Centripetal force is written as

$F_c = m\frac{v^2}{r}$

with v the linear velocity and r the radius of the turntable. We are not given v, but we can write it as

$v = r\omega$

with ω denoting the angular velocity, which we are given. With that, the above becomes:

$F_c = m\frac{v^2}{r}=m\omega^2 r$

Now, the friction force must be at least as much (in magnitude) as Fc. The coefficient (static) of friction μ must be large enough. How large?

$F_r=\mu mg \geq m\omega^2 r = F_c\implies\\\mu \geq \frac{\omega^2 r}{g}$

Let's plug in the numbers. The angular velocity should be in radians per second. We are given rev/min, which can be easily transformed by a factor 2pi/60:

$\frac{1 rev}{1 min}\cdot\frac{\frac{2\pi rad}{rev}}{\frac{60s}{1 min}}=\frac{2\pi}{60}\frac{rad}{s}$

and so 45 rev/min = 4.71 rad/s.

$\mu \geq \frac{\omega^2 r}{g}=\frac{4.71^2\frac{1}{s^2}\cdot 0.12m}{9.8\frac{m}{s^2}}=0.27$

A static coefficient of friction of at least be 0.27 must be present for the bug to continue enjoying the ride on the turntable.

3 0

3 years ago