Ask question

Ask question

All categories

4 years ago

15

Jak możemy służyć innym ludziom. Pilne

1 answer:

Troyanec [42]4 years ago

7 0

Could u put it in english u can use goggle translation if u do not know how to

You might be interested in

Two objects exert a gravitational force of 3 N on one another when they are 10 m apart. What would that force be if the distance

jeka94

Gravitational force = G ( m1 m2 ) / r²
3 = G ( m1 m2 ) / ( 10 )²x = G ( m1 m2 ) / ( 5 )²We shall divide those two equations:3 / x = 1/100 / 1/25 = 25 / 100 = 1 / 4x · 1 = 3 · 4x = 12Answer:C. 12 N

8 0

3 years ago

A food department is kept at â12Â°c by a refrigerator in an environment at 30Â°c. the total heat gain to the food department is

slava [35]

As per energy conservation in the reversible engine we can say

$Q_2 + W = Q_1$

here we know that

$Q_2 = 3300 kJ/h$

$Q_1 = 4800 kJ/h$

now from above equation

$3300 + W = 4800$

$W = 1500 kJ/h$

now we can convert it into kW

$W = 1500\times \frac{kJ}{3600s}$

$W = 0.42 kW$

so above is the power input to the refrigerator

now to find COP we know that

$COP = \frac{Q_2}{W}$

$COP = \frac{3300}{1500} = 2.2$

so COP of refrigerator is 2.2

3 0

3 years ago

Calculate the speed of a bike rider who accelerates (from rest) for 5 seconds down a hill at an acceleration of 8

olya-2409 [2.1K]

Answer:

speed=abs(v)=40ms^-1

Explanation:

acceleration, a = (v-u)/t

since initial velocity u=0 (at rest) and a=8ms^-2,

8=v/5

hence after 5 seconds, v=40ms^-1

6 0

3 years ago

A 1.0 meter long rod is held horizontally in the east-west direction on a distant planet and is dropped from a height of 1.23 m.

enyata [817]

Answer:

The induced emf between two end is $34.02 \times 10^{-5}$ V

Explanation:

Given:

Length of rod $l = 1$ m

Height $h = 1.23$ m

Magnetic field $B = 6.93 \times 10^{-5}$ T

For finding induced emf,

$\epsilon = Blv$

Where $v =$ velocity of rod,

For finding the velocity of rod.

From kinematics equation,

$v^{2} = v_{o} ^{2} + 2gh$

Where $v_{o} =$ initial velocity, $g = 9.8 \frac{m}{s^{2} }$

$v = \sqrt{2gh}$

$v = \sqrt{2 \times 9.8 \times 1.23}$

$v = 4.91$ $\frac{m}{s}$

Put the velocity in above equation,

$\epsilon = 6.93 \times 10^{-5} \times 1 \times 4.91$

$\epsilon = 34.02 \times 10^{-5}$ V

Therefore, the induced emf between two end is $34.02 \times 10^{-5}$ V

6 0

3 years ago

galina1969 [7]

Answer:

72%

Calculating Efficiency:

The amount of work obtained from a machine is always less than the amount of work put into it. Thisis because some of the work is lost due to friction. The efficiency of a machine can be calculated usingthe following formula:Percent Efficiency = (work output-Machine / work input-You) x 100%

8 0

2 years ago