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3 years ago

Which best describes internet wikis as a source of scientific information

Physics

1 answer:

scoundrel [369]3 years ago

5 0

Answer:

They are written or edited by anyone

Explanation:

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A driver notices that her 1280 kg car slows down from 92 km/h to 68 km/h in about 7.5 s on the level when it is in neutral. Appr

sweet-ann [11.9K]

Answer:

P = 25299.75 watts

Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts

Explanation:

Given;

Mass of car m = 1280kg

initial speed v1 = 92km/h = 92×1000/3600 m/s= 25.56m/s

Final speed v2 = 68km/h = 68×1000/3600 m/s= 18.89m/s

time taken t = 7.5s

Change in the kinetic energy of the car within that period;

∆K.E = 1/2 ×mv1^2 - 1/2 × mv2^2

∆K.E = 0.5m(v1^2 -v2^2)

Substituting the values, we have;

∆K.E = 0.5×1280(25.56^2 - 18.89^2)

∆K.E = 189748.16J

Power used during this Change;

Power P = ∆K.E/t

Substituting the values;

P = 189748.16/7.5

P = 25299.75 watts

Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts

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3 years ago

Is this wave transverse or longitudinal

lys-0071 [83]

It depends on if it is a sound wave or light wave

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3 years ago

What is malware short for?

yaroslaw [1]

The correct answer is C

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3 years ago

Jennifers bowling ball is dropped from rest. Janets bowling ball is thrown horizontally at the same time. After the balls are re

Pachacha [2.7K]

They both have a constant acceleration of g (9.8 m/s) So they both have equal accelerations. This is according to the law of gravity

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3 years ago

Read 2 more answers

Suppose a child drives a bumper car head on into the side rail, which exerts a force of 3900 N on the car for 0.55 s. Use the in

-Dominant- [34]

Answer:

The impulse is 2145 kg-m/s

The final velocity is -8.34 m/s or 8.34 m/s in he opposite direction.

Explanation:

Force on the rail = 3900 N

Elapsed time of impact = 0.55 s

Impulse is the product of force and the time elapsed on impact

I = Ft

I is the impulse

F is force

t is time

For this case,

Impulse = 3900 x 0.55 = 2145 kg-m/s

If the initial velocity was 2.95 m/s

and mass of car plus driver is 190 kg

neglecting friction, the initial momentum of the car is given as

P = mv1

where P is the momentum

m is the mass of the car and driver

v1 is the initial velocity of the car

initial momentum of the car P = 2.95 x 190 = 560.5 kg-m/s

We know that impulse is equal to the change of momentum, and

change of momentum is initial momentum minus final momentum.

The final momentum = mv2

where v2 is the final momentum of the car.

The problem translates into the equation below

I = mv1 - mv2

imputing values, we have

2145 = 560.5 - 190v2

solving, we have

2145 - 560.5 = -190v2

1584.5 = -190v2

v2 = -1584.5/190 = -8.34 m/s

6 0

3 years ago