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3 years ago

I need help with homework! what should i choose as the greatest british invention?

1 answer:

4 0

THE MINI Alec Issigonis, 1959
The Telephone Alexander Graham Bell, 1876

http://www.radiotimes.com/news/2013-01-08/the-50-greatest-british-inventions

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What forms when two continental plates collide?

Jlenok [28]

When tectonic plates collide, this is a convergent plate boundary.
When the two plates at a convergent boundary are continental, they form mountains and mountain ranges.

Hope this helps! :)

8 0

3 years ago

A child whose weight is 287 N slides down a 7.20 m playground slide that makes an angle of 31.0Â° with the horizontal. The coeff

natulia [17]

Answer:

$H =212.6 \ J$

$v = 7.647 \ m/s$

Explanation:

From the question we are told that

The child's weight is $W_c = 287 \ N$

The length of the sliding surface of the playground is $L = 7.20 \ m$

The coefficient of friction is $\mu = 0.120$

The angle is $\theta = 31.0 ^o$

The initial speed is $u = 0.559 \ m/s$

Generally the normal force acting on the child is mathematically represented as

=> $N = mg * cos \theta$

Note $m * g = W_c$

Generally the frictional force between the slide and the child is

$F_f = \mu * mg * cos \theta$

Generally the resultant force acting on the child due to her weight and the frictional force is mathematically represented as

$F =m* g sin(\theta) - F_f$

Here F is the resultant force and it is represented as $F = ma$

=> $ma = m* g sin(31.0) - \mu * mg * cos (31.0)$

=> $a = g sin(31.0)- \mu * g * cos (31.0)$

=> $a = 9.8 * sin(31.0) - 0.120 * 9.8 * cos (31.0)$

=> $a = 4.039 \ m/s^2$

$F_f = 0.120 * 287 * cos (31.0)$

=> $F_f = 29.52 \ N$

Generally the heat energy generated by the frictional force which equivalent tot the workdone by the frictional force is mathematically represented as

$H = F_f * L$

=> $H = 29.52 * 7.2$

=> $H =212.6 \ J$

Generally from kinematic equation we have that

$v^2 = u^2 + 2as$

=> $v^2 = 0.559^2 + 2 * 4.039 * 7.2$

=> $v = \sqrt{0.559^2 + 2 * 4.039 * 7.2}$

=> $v = 7.647 \ m/s$

6 0

3 years ago

PLEASE ANSWER QUESTION 25! NOT 24. Brainliest and 25 points!

Inessa05 [86]

D) Guard against a short circuit electrocuting a user.

"The 4-wire setup is inherently safer and better able to prevent electrical shock, which in the case of a 220/240-volt circuit can be fatal."

5 0

3 years ago

Read 2 more answers

If the input work on a machine is equal to it's output work. the machine has _____ efficiency.

AleksAgata [21]

Answer:

100% efficiency

Explanation:

the machine has _100%_ efficiency.

(fill in the blank)

7 0

3 years ago

If you live in a very cold area, you may have seen the depth of a bank of snow shrink even though temperatures remain below the

Aleks04 [339]

<span>To answer the question above, if the day sky is clear it collects radiation. If air is dry snow sublimates faster. If both cases overlap it disappears faster where ever coldest. Thank you for posting your question here. I hope my answer helps. </span>

7 0

3 years ago