Pls help i need an answer for this ill mark u brianlist or anything u want

Why isn't the atomic mass always a whole number

aev [14]

Because electrons add to the atomic mass, while it is very slim (around 1/2000 of a proton) their mass is what causes the decimals on atomic masses

6 0

3 years ago

A thunderstorm starts to form when water evaporates to form clouds. Which of the following best explains why thunderstorms usual

Morgarella [4.7K]

Thunderstorms might form on warm days simply because heat is what causes evaporation, causing rain. Thunderstorms also form when the atmosphere is unstable! Meaning the hot air is above the cold air, evaporation occurs, it rains, and then rapid expansion of heat in the air caused by lighting causes thunder.

5 0

3 years ago

During her high bar routine from question 2, Gabby Douglas slipped and falls from the high bar, landing on a 10 cm thick gymnast

tankabanditka [31]

a) 122.5 J

b) -122.5 J

c) -1884.6 N

d) -3769.2 N

e) $-753.8 m/s^2$

f) $a=-76.9 g$

Explanation:

a)

The kinetic energy of an object is the energy possessed by the object due to its motion.

Mathematically, it is given by:

$K=\frac{1}{2}mv^2$

where

m is the mass of the object

v is the speed of the object

Here, we want to find the kinetic energy of the head just before hitting the mat.

At that instant, the speed is:

v = 7 m/s

The mass of the head is:

m = 5 kg

So, the kinetic energy is

$K=\frac{1}{2}(5)(7)^2=122.5 J$

b)

According to the work-energy theorem, the work done by a force on an object is equal to the change in kinetic energy of the object:

$W=K_f - K_i$

where

W is the work done

$K_f$ is the final kinetic energy

$K_i$ is the initial kinetic energy

In this problem:

$K_i=122.5 J$ is the kinetic energy of the head just before hitting the mat

$K_f=0 J$ is the final kinetic energy (since the head comes to a stop)

So, the work done by the mat is:

$W=0-122.5 = -122.5 J$

The work is negative because the force exerted by the mat is opposite to the direction of motion of the head.

c)

The work exerted by a force on an object is given by

$W=Fd$

where

F is the force applied

d is the displacement of the object

W is the work done

In this problem:

W = -122.5 J is the work done by the mat on the head

d = 6.5 cm = 0.065 m is the displacement of the head (since it deflects the mat by this amount)

So, the average force exerted by the mat on the head is:

$F=\frac{W}{d}=\frac{-122.5}{0.065}=-1884.6 N$

(the negative sign indicates that the force is in direction opposite to the motion of the head)

d)

The force calculated in part d) represents the average force exerted by the mat on the head:

$F_{avg}=-1884.6 N$

We can assume that as the head first hits the mat, the initial force is zero, then increases at a constant rate up to a peak value of $F_{peak}$ , then it decreases again until the head stops.

In this case, the relationship between average force and peak force is:

$F_{avg}=\frac{0+F_{peak}}{2}$

And therefore, the peak impact force exerted by the mat on the head is:

$F_{peak}=2F_{avg}=2(1884.6)=-3769.2 N$

e)

The peak acceleration of the head can be found by using Newton's second law, which states that:

$F=ma$

where

F is the force on the head

m is the mass of the head

a is the acceleration

Here we have:

F = -3769.2 N is the peak force

m = 5 kg is the mass of the head

So, solving for the acceleration, we find:

$a=\frac{F}{m}=\frac{-3769.2}{5}=-753.8 m/s^2$

f)

The value of the acceleration due to gravity is

$g=9.8 m/s^2$

Here we want to express the peak acceleration of the head in terms of the acceleration due to gravity; so we can write:

$a=Ng$

where

$a=-753.8 m/s^2$ is the peak acceleration

N is the ratio between the peak acceleration and the gravity acceleration

Solving for N,

$N=\frac{a}{g}=\frac{-753.8}{9.8}=-76.9$

This means that the peak acceleration can be written as

$a=-76.9 g$

6 0

3 years ago

Write about the similarities and differences between kinetic and potential energy. Include specific, real world example in your

lord [1]

Answer:

Energy is transformed from potential to kinetic and vice versa

Explanation:

The energy is transformed from mechanical to kinetic energy when the object changes its position with respect to a reference point, where it loses height but increases its speed. When the object is at maximum height with respect to a reference point, it will have its maximum potential energy value. When the object passes through the reference point it will have potential energy equal to zero, but this energy will become kinetic energy.

The most characteristic and real example is that of a pendulum at one end, as can be seen in the attached image.

When the pendulum is located at the top end, as shown in Figure 1, at that point the maximum potential energy will be held. Then the pendulum is released and when it passes through the reference point and its height is zero, with respect to that point, all potential energy will have become kinetic energy in the same way at this point the maximum speed of the pendulum will be set.

8 0

3 years ago

Date the law of conversation of energy

Margaret [11]

Answer:

In its most compact form, it states: matter is neither created nor destroyed. In 1842, Julius Robert Mayer discovered the Law of Conservation of Energy.

Explanation:

3 0

3 years ago