3 years ago

Please help me with this review question.

Physics

1 answer:

jolli1 [7]3 years ago

8 0

Answer:

28.7%

Explanation:

efficiency = work output /work input × 100

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You weigh 580 N on Earth. If you were to go to Mars, where its gravitational pull is 3 . 7 11 m /s 2 , what would you weigh? (Hi

andrew-mc [135]

Answer:

59.18 kg

Explanation:

use f=ma

f= 580 N

a = 9.8 m/s 2

weigh(m) doesn't change only force(F) changes

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3 years ago

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A 0.2 kg block sliding on a horizontal table slows down from 25 m/s to 20 m/s. How much energy does the block lose due to fricti

Papessa [141]

Answer:

the kinetic energy lost due to friction is 22.5 J

Explanation:

Given;

mass of the block, m = 0.2 kg

initial velocity of the block, u = 25 m/s

final velocity of the block, v = 20 m/s

The kinetic energy lost due to friction is calculated as;

$\Delta K.E= K.E_f - K.E_i\\\\\Delta K.E= \frac{1}{2}mv^2 - \frac{1}{2}mu^2\\\\\Delta K.E= \frac{1}{2}m(v^2 -u^2)\\\\\Delta K.E= \frac{1}{2} \times 0.2 (20^2 - 25^2)\\\\\Delta K.E= -22.5 \ J$

Therefore, the kinetic energy lost due to friction is 22.5 J

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3 years ago

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The chemical symbol for the element calcium is Ca. What would be the symbol representing calcium atoms that have lost two electr

Kazeer [188]

Answer:

$ca^{2 + }$

Explanation:

In all atoms, the number of protons = number of electrons, as a result the atom is neutral. Losing or gaining electrons will make the atom electrically charged and we call an electrically charged atom an ion.

Ca 2+ would be the symbol because losing two negative electrons makes calcium's nucleus more positive by two protons.

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3 years ago

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How many elements are in the mixture pictured?<br> A. 7<br> B. 4<br> C. 3<br> D. 2

alex41 [277]

Answer:

C: 3

Explanation:

Cause of the colors

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2 years ago