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2 years ago

Worth 20 points Please answer showing the conversions

Physics

1 answer:

vladimir1956 [14]2 years ago

4 0

Answer:

b) 18 m/s is the correct answer.

Explanation:

initial velocity(u) = 30m/s

acceleration(a) = -4m/s²

time(t) = 3 seconds

final velocity(v) = ?

using the formula,

a = (v-u)/t

or, -4 = (v-30)/3

or, -12 = v-30

or, v = -12+30

so, v = 18 m/s

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For a huge luxury liner to move with constant velocity, its engines need to supply a forward thrust of 7.45 105 N. What is the m

ehidna [41]

Answer:

7.45 10^5N.

Explanation:

according to newtons second law of motion;

$\sum F_x = ma_x\\F_{app} - F_r = ma_x$

Fapp is the applied force

Fr is the resistive force

m is the mass of the luxury

a is the acceleration

Since the huge luxury liner move with constant velocity, then acceleration is zero i.e a = 0. The equation becomes;

$F_{app} - F_f = m(0)\\F_{app} - F_f =0\\F_{app} = F_f$

This shows that the applied force will be equal to the resistive force if the velocity is constant.

Given Fr = 7.45 10^5 N therefore the resistive force will also be 7.45 10^5N.

Hence the magnitude of the resistive force exerted by the water on the cruise ship is 7.45 10^5N.

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3 years ago

Which sizes influence the adhesive and rolling friction?

julsineya [31]

juju on that beat

Explanation:

4 0

3 years ago

Identify which best describes the energy used to pluck guitar strings to make sound.

Novay_Z [31]

The correct answer is: Mechanical Energy

Explanation:
As the guitar strings are plunked, the potential energy stored in the strings has an ability to make them vibrate. When the strings are vibrating, that potential energy is actually converted to the kinetic energy. Hence, the whole phenomena contains both the kinetic energy and the potential energy. The sum of kinetic energy and the potential energy is called Mechanical energy. Therefore, the correct answer is Mechanical Energy.

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3 years ago

Read 2 more answers

Four identical metallic objects carry the following charges 1.82 6.65 4.80 and 9.30 C The objects are brought simultaneously int

GuDViN [60]

Answer:

a) 5.64 C

b) 3.5*10¹⁹ protons

Explanation:

Since the four metallic objects are identical, and total charge must be conserved, this means that after brought simultaneously into contact so that each touches the others, once separated, total charge must be the same than before being brought in contact.
But due they are identical, after charges were able to transfer freely between them, the four objects must have the same final charge, i.e. the fourth part of the total charge, as follows:

$Q_{n} = \frac{Q_{tot}}{4} = \frac{22.57C}{4} = 5.64 C (1)$

This charge will be divided between n protons, since the charge is positive.
Since each proton carries a charge equal to the elementary charge e, which value is 1.6*10⁻¹⁹ C, we can find the number of protons in excess, doing the following calculation:
$n_{p} =\frac{Q_{n}}{e} = \frac{5.64C}{1.6e-19C} = 3.5 e19 C (2)$

7 0

3 years ago

A housefly walking across a clean surface can accumulate a significant positive or negative charge. In one experiment, the large

nalin [4]

Answer:

1681714.28571 N/C

Yes it could exist

Explanation:

m = Mass of housefly = 12 m

q = Charge = 70 pC

g = Acceleration due to gravity = 9.81 m/s²

E = Electric field

When an object accumulates charge it means that it is gaining electrons making it negatively charged. This is the concept of static electricity.

Here, the electric force and the graviational force will balance each other

$F_e=W\\\Rightarrow qE=mg\\\Rightarrow E=\frac{mg}{q}\\\Rightarrow E=\frac{12\times 10^{-6}\times 9.81}{70\times 10^{-12}}\\\Rightarrow E=1681714.28571\ N/C$

1681714.28571 N/C of electric field would be required to levitate

The direction of the electric field would be upwards vertically.

In air the critical value of electric field is $3\times 10^6\ N/C$ which is more than the critical value of electric field in air. So, the electric field can exist.

5 0

3 years ago