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3 years ago

Question 1 Unsaved

Physics

2 answers:

Ne4ueva [31]3 years ago

8 0

Fusion and gravity is ur answer

r-ruslan [8.4K]3 years ago

4 0

The correct answer is:

fusion and gravity

In fact:

- Nuclear fusion: the fusion of lighter nuclei into heavier nuclei release large amounts of energy, and this energy "pushes" outwards the star, balancing the gravitational force

- Gravity: the Sun has a huge mass, so there is a strong gravitational force pushing towards the centre of our star. Without the action of the nuclear fusion, the star would collapse due to the effect of the gravity.

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The near point of an eye is 110 cm. A corrective lens is to be used to allow this eye to focus clearly on objects 26.0 cm in fro

irga5000 [103]

Answer:

The focal length of the lens is 34.047 cm

The power of the needed corrective lens is 2.937 diopter.

Explanation:

Distance of the object from the lens,u = 26 cm

Distance of the image from the lens ,v= -110 cm

(Image is forming on the other side of the lens)

Since ,lens of the human eye is converging lens,convex lens.

Using a lens formula:

$\frac{1}{f}=\frac{1}{u}+\frac{1}{v}$

$\frac{1}{f}=\frac{1}{26 cm}+\frac{1}{-110 cm}$

f = 34.047 cm = 0.3404 m

Power of the lens = P

$P=\frac{1}{f}=\frac{1}{0.34047 m}=2.937 diopter$

6 0

3 years ago

A 165 N object is supported by three cables(T1, T2 and T3), of which T1 and T2 are making angles θ1 = 52o and θ2 = 39o as shown

Liono4ka [1.6K]

Answer:

?Tension in string 2, T2 (in Newton) =

Answer for part 2

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3 0

3 years ago

A 4.79 g bullet moving at 642.3 m/s penetrates a tree trunk to a depth of 4.35 cm. Use work and energy considerations to find th

vladimir1956 [14]

Answer:

Force, $F=2.27\times 10^4\ N$

Explanation:

Given that,

Mass of the bullet, m = 4.79 g = 0.00479 kg

Initial speed of the bullet, u = 642.3 m/s

Distance, d = 4.35 cm = 0.0435 m

To find,

The magnitude of force required to stop the bullet.

Solution,

The work energy theorem states that the work done is equal to the change in its kinetic energy. Its expression is given by :

$F.d=\dfrac{1}{2}m(v^2-u^2)$

Finally, it stops, v = 0

$F.d=-\dfrac{1}{2}m(u^2)$

$F=\dfrac{-mu^2}{2d}$

$F=\dfrac{-0.00479\times (642.3)^2}{2\times 0.0435}$

F = -22713.92 N

$F=2.27\times 10^4\ N$

So, the magnitude of the force that stops the bullet is $2.27\times 10^4\ N$

7 0

3 years ago

Under which conditions do both convex and concave mirrors form virtual images? State whether or not each can form a real image.I

natali 33 [55]

Concave mirrors can make a real image.when the object is away from the mirror it is called real image and when the object is closer to the mirror it is called virtual mirror.

8 0

3 years ago

Read 2 more answers

The concrete sections of a certain superhighway are designed to have a length of 23.0 m. The sections are poured and cured at 10

loris [4]

Answer:

0.88 cm

Explanation:

Initial length at 10°c, L = 23 m

Rise of temperature, Δt = 42 - 10 = 32°c

Coefficient of linear expansion of concrete, α = 12 x 10^(-6) per°c

Minimum spacing to be left = α L Δt

$=12\times10^{-6}\times23\times32$

$=8.832\times10^{-3}m$

= 8.832 x 10^{-1} cm

= 0.88 cm

Note: I have a chosen a general value of 12 x 10^-6 per deg c for coefficient of expansion of concrete. However, please refer to the value given in your text book and substitute it for an accurate answer.

8 0

3 years ago