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2 years ago

7

How much distance does it take to stop a car going 30 m/s (67 mph) if the brakes can apply a force equal to one half the car’s w

eight?

1 answer:

denpristay [2]2 years ago

5 0

Answer:

0

rqc3fgt9uwgtd.ojbxrfdgi8ubvg iohy

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what us the velocity in meters per second of a runner who runs exactly 110 m toward the beach in 72 secs

finlep [7]

Velocity = Distance / time taken

= 110 m /72s

1.52 ms⁻¹

4 0

3 years ago

The diagram above shows four light bulbs wired in a circuit. What would happen if bulb 3 burned out

andre [41]

The lights will no longer work because the circuit will be cut

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3 years ago

Two deuterium nuclei, H, fuse to produce a tritium nucleus, H, and a hydrogen nucleus. A neutral deuterium atom has a mass of 2.

Nesterboy [21]

<u>Answer:</u> The amount of energy released in the process is 4.042 MeV.

<u>Explanation:</u>

The chemical reaction for the fusion of deuterium nucleus follows the equation:

$_1^2\textrm{H}+_1^2\textrm{H}\rightarrow _1^3\textrm{H}+_1^1\textrm{H}$

Atomic mass of the nucleus also contains some mass of the electrons.

Mass of electron in $MeV/c^2$ is $0.511MeV/c^2$

<u>Calculating the mass of deuterium nucleus:</u>

$m(_1^2\textrm{H})=(2.014102u)\times (931.494MeV/c^2.u)-\text{Mass of electron}$

So, initial mass of the reaction = $2[(1876.124MeV/c^2)-(0.511MeV/c^2)]=3751.226MeV/c^2$

<u>Calculating the mass of tritium nucleus:</u>

$m(_1^3\textrm{H})=(3.106049u)\times (931.494MeV/c^2.u)-\text{Mass of electron}$

$m(_1^3\textrm{H})=(3.106049u)\times (931.494MeV/c^2.u)-(0.511MeV/c^2)=2803.921MeV/c^2$

So, final mass of the reaction = $2803.921-[(1.007267u\times 931.494MeV/c^2.u)]=3747.184$

Difference between the masses of the nucleus:

$\Delta m=m_{initial}-m_{final}\\\\\Delta m=(3751.226-3747.184)MeV/c^2=4.042MeV/c^2$

Energy released in the process is calculated by using Einstein's equation, which is:

$E=\Delta mc^2$

Putting value of $\Delta m$ in above equation, we get:

$E=(4.042MeV/c^2)\times c^2\\\\E=4.042MeV$

Hence, the amount of energy released in the process is 4.042 MeV.

4 0

3 years ago

..................................<br>.

vivado [14]

Answer: there is 36 dots

7 0

3 years ago

Not allowed to use kinematics

KIM [24]

Answer:

A. 131.9 s

B. 0.13 m/s

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 490 Kg

Height (h) = 17 m

Power (P) = 0.83 hp

Time (t) =?

Velocity (v) =.?

Next, we shall convert 0.83 hp to Watts. This can be obtained as follow:

1 hp = 745.7 Watts

Therefore,

0.83 hp = 0.83 hp × 745.7 Watts / 1 hp

0.83 hp = 618.931 Watts

Thus, 0.83 hp is equivalent to 618.931 Watts.

A. Determination of the time.

Mass (m) = 490 Kg

Height (h) = 17 m

Power (P) = 618.931 Watts

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =?

Power = Energy / time

P = mgh / t

618.931 = 490 × 9.8 × 17 / t

618.931 = 81634 / t

Cross multiply

618.931 × t = 81634

Divide both side by 618.931

t = 81634 / 618.931

t = 131.9 s

Therefore, it will take 131.9 s to lift the beam.

B. Determination of the constant velocity.

We'll begin by calculating the force. This can be obtained as follow:

Mass (m) = 490 Kg

Acceleration due to gravity (g) = 9.8 m/s²

Force (F) =?

Force = mass × acceleration

Force = 490 × 9.8

Force = 4802 N

Finally, we shall determine the constant velocity as follow:

Force (F) = 4802 N

Power (P) = 618.931 Watts

Velocity (v) =?

P = F × v

618.931 = 4802 × v

Divide both side by 4802

v = 618.931 / 4802

v = 0.13 m/s

Thus, the constant speed at which the beam moves upward is 0.13 m/s

4 0

3 years ago