(25 Brainly Points.)

Atomic nuclei are made of protons and neutrons. This fact by itself shows thatthere must be some other type of force in addition

Stells [14]

Protons and neutrons are packed together in a very small region called nucleus. Protons are positively charged and we know that like charges repel. Then how is it that protons are not repelling each other and flying away from nucleus?

You may think that gravitational force is holding all the protons together but it is not so. Gravitational force is many times weaker than repulsive force.

It is actually strong force which holds proton together. At this short distance, strong force comes into play and is several times stronger than the repulsive force.

5 0

3 years ago

V=xf-xi/t solve for t

irina [24]

Answer:

$t=\frac{x_f-x_i}{v}$

Explanation:

Starting from the equation:

$v=\frac{x_f-x_i}{t}$

First of all, let's multiply by t on both sides:

$v\cdot t = \frac{x_f-x_i}{t}\cdot t \\vt = x_f - x_i$

And then, let's divide by v on both sides:

$\frac{vt}{v}=\frac{x_f-x_i}{v}\\t=\frac{x_f-x_i}{v}$

So, finally

$t=\frac{x_f-x_i}{v}$

7 0

3 years ago

The force exerted by the wind on the sails of a sailboat is Fsail = 330 N north. The water exerts a force of Fkeel = 210 N east.

Elena L [17]

Answer:

The magnitude of the acceleration is $a_r = 1.50 \ m/s^2$

The direction is $\theta = 32.5 6^o$ north of east

Explanation:

From the question we are told that

The force exerted by the wind is $F_{sail} = (330 ) \ N \ north$

The force exerted by water is $F_{keel} = (210 ) \ N \ east$

The mass of the boat(+ crew) is $m_b = 260 \ kg$

Now Force is mathematically represented as

$F = ma$

Now the acceleration towards the north is mathematically represented as

$a_n = \frac{F_{sail}}{m_b}$

substituting values

$a_n = \frac{330 }{260}$

$a_n = 1.269 \ m/s^2$

Now the acceleration towards the east is mathematically represented as

$a_e = \frac{F_{keel}}{m_b }$

substituting values

$a_e = \frac{210}{260}$

$a_e =0.808 \ m/s^2$

The resultant acceleration is

$a_r = \sqrt{a_e^2 + a_n^2}$

substituting values

$a_r = \sqrt{(0.808)^2 + (1.269)^2}$

$a_r = 1.50 \ m/s^2$

The direction with reference from the north is evaluated as

Apply SOHCAHTOA

$tan \theta = \frac{a_e}{a_n}$

$\theta = tan ^{-1} [\frac{a_e}{a_n } ]$

substituting values

$\theta = tan ^{-1} [\frac{0.808}{1.269 } ]$

$\theta = tan ^{-1} [0.636 ]$

$\theta = 32.5 6^o$

5 0

3 years ago

A 1.5-kilogram cart initially moves at 2.0 meters per second. It is brought to rest by a constant net force in 0.30 second. What

AnnZ [28]

Acceleration = (change in speed) / (time for the change)

Change in speed = (speed at the end) minus (speed at the beginning.

The cart's acceleration is

 (0 - 2 m/s) / (0.3 sec)

 = ( -2 / 0.3 ) (m/s²) = -(6 and 2/3) m/s² .

Newton's second law of motion says

 Force = (mass) x (acceleration) .

For this cart: Force = (1.5 kg) x ( - 6-2/3 m/s²)

 = ( - 1.5 x 20/3 ) (kg-m/s²)

 = - 10 newtons .

The force is negative because it acts opposite to the direction 
in which the cart is moving, it causes a negative acceleration, 
and it eventually stops the cart.

6 0

3 years ago

Please help ASAP!!

inessss [21]

Answer:

at t=46/22, x=24 699/1210 ≈ 24.56m

Explanation:

The general equation for location is:

x(t) = x₀ + v₀·t + 1/2 a·t²

Where:

x(t) is the location at time t. Let's say this is the height above the base of the cliff.

x₀ is the starting position. At the base of the cliff we'll take x₀=0 and at the top x₀=46.0

v₀ is the initial velocity. For the ball it is 0, for the stone it is 22.0.

a is the standard gravity. In this example it is pointed downwards at -9.8 m/s².

Now that we have this formula, we have to write it two times, once for the ball and once for the stone, and then figure out for which t they are equal, which is the point of collision.

Ball: x(t) = 46.0 + 0 - 1/2*9.8 t²

Stone: x(t) = 0 + 22·t - 1/2*9.8 t²

Since both objects are subject to the same gravity, the 1/2 a·t² term cancels out on both side, and what we're left with is actually quite a simple equation:

46 = 22·t

so t = 46/22 ≈ 2.09

Put this t back into either original (i.e., with the quadratic term) equation and get:

x(46/22) = 46 - 1/2 * 9.806 * (46/22)² ≈ 24.56 m

4 0

3 years ago