Which two terms describe the relationship between the two variables in this graph?

A factory worker pushes a 30.0-kg crate a distance of 4.5 m along a level floor at constant velocity by pushing horizontally on

SIZIF [17.4K]

(a) 73.5 N

The velocity of the crate is constant: this means that the acceleration is zero (a=0), so according to Newton's second law

$\sum F = ma$

the resultant of the forces must be zero: $\sum F = 0$ (1)

The motion is along the horizontal direction, so we are only interested in the forces acting along this direction. There are two of them:

$F$ , the push applied by the worker

$F_f=-\mu mg$ , the force of friction, with $\mu=0.25$ being the coefficient of friction, $m=30.0 kg$ being the mass of the crate, and $g=9.8 m/s^2$ . The negative sign is due to the fact that the friction acts in the opposite direction to the motion. Eq.(1) then becomes

$F-\mu mg=0\\F=\mu mg=(0.25)(30.0 kg)(9.8 m/s^2)=73.5 N$

So, this is the force that the worker must apply.

(b) 330.8 J

The work done by the pushing force of the worker on the crate is given by:

$W=Fd cos \theta$

where

F = 73.5 N is the force

d = 4.5 m is the displacement

$\theta=0^{\circ}$ is the angle between the direction of the force and the displacement (0 degrees, since they are in same direction)

Substituting, we have

$W=(73.5 N)(4.5 m)(cos 0^{\circ})=330.8 J$

(c) -330.8 J

To calculate the work done by friction, we apply the same formula:

$W=F_f d cos \theta$

where

$F_f = \mu mg=(0.25)(30.0 kg)(9.8 m/s^2)=73.5 N$ is the magnitude of the force of friction

d = 4.5 m is the displacement

$\theta=180^{\circ}$ is the angle between the direction of the force of friction and the displacement (it is 180 degrees since the two are into opposite directions)

Substituting, we find

$W=(73.5 N)(4.5 m)(cos 180^{\circ})=-330.8 J$

So, the work done by friction is negative.

(d) 0 J

As before, the work done by any force on the crate is

$W=F_f d cos \theta$

We notice that both gravity and normal force are perpendicular to the displacement: therefore, $\theta=90^{circ}$ , and so

$cos \theta=0$

which means that the work done by both forces is zero.

(e) 0 J

The total work done on the crate is the sum of the work done by the four forces acting on it, so:

$W=W_{push} + W_{friction}+W_{gravity}+W_{normal}=330.8J-330.8J+0+0=0$

And this is in accordance with the work-energy theorem, which states that the variation of kinetic energy of the crate is equal to the work done on it: since the crate is moving at constant velocity, its variation of kinetic energy is zero, as well as the work done on it.

5 0

3 years ago

How does inertia affect a person who is not wearing a seatbelt during a collision?

ELEN [110]

A person who is not wearing a seatbelt during a collision will be thrown forward because it maintains forward motion

<h3>Further explanation </h3>

In Newton's law, it is stated that if the resultant force acting on an object of magnitude is zero, it can be formulated :

$\large{\boxed{\bold{\Sigma F = 0}}}$

then the object tends to defend itself from its state. So for objects in a state of movement, objects tend to move forever. Likewise, for objects in a state of rest, they tend to remain forever. The tendency of objects like this is called<em> inertia </em>

The size of inertia is proportional to mass, the greater the mass of the object, the greater the inertia of the object.

In objects with mass m that move translatively, the object will maintain its linear velocity

When we are in a vehicle that moves forward, then we will still maintain a state of forwarding motion. If our vehicle stops suddenly, then we keep moving forward so we will be pushed forward. From this point, the use of a safety belt serves to hold back our movements so that there are no fatal accidents or collisions.

<h3>Learn more </h3>

Newton's law of inertia

brainly.com/question/1412777

example of Newton's First Law of inertia

brainly.com/question/1090504

law of motion

brainly.com/question/75210

Keywords: inertia, Newton's First Law

7 0

3 years ago

Read 2 more answers

Light of wavelength 520 nm is used to illuminate normally two glass plates 21.1 cm in length that touch at one end and are separ

Oksi-84 [34.3K]

Answer:

The number is $Z = 216 \ fringes$

Explanation:

From the question we are told that

The wavelength is $\lambda = 520 \ nm = 520 *10^{-9} \ m$

The length of the glass plates is $y = 21.1cm = 0.211 \ m$

The distance between the plates (radius of wire ) = $d = 0.028 mm = 2.8 *10^{-5} \ m$

Generally the condition for constructive interference in a film is mathematically represented as

$2 * t = [m + \frac{1}{2} ]\lambda$

Where t is the thickness of the separation between the glass i.e

t = 0 at the edge where the glasses are touching each other and

t = 2d at the edge where the glasses are separated by the wire

m is the order of the fringe it starts from 0, 1 , 2 ...

So

$2 * 2 * d = [m + \frac{1}{2} ] 520 *10^{-9}$

=> $2 * 2 * (2.8 *10^{-5}) = [m + \frac{1}{2} ] 520 *10^{-9}$

=>

$m = 215$

given that we start counting m from zero

it means that the number of bright fringes that would appear is

$Z = m + 1$

=> $Z = 215 +1$

=> $Z = 216 \ fringes$

3 0

3 years ago

Light Bulb

Allushta [10]

Answer:

In my opinion I think it's B I'm so sorry if I get this wrong

8 0

3 years ago

Name and describe the three quantized particles

padilas [110]

Answer:

The three quantized particles are:

1. Electrons

2. Protons

3. Neutrons

Explanation:

Quantization can be defined as the conversion of a continuous quantity into discrete set of values.

It can also be defined as the concept which says that the particles exist as the smallest finite and discrete value known as quanta which not be divided further.

The three particles include:

1. The electron bound inside an atom have quantized momentum and energy.

2. The proton bound in the inside of a nucleus has energy in the quantized form only.

3. Also the nucleus bound neutron is also a quantized particle.

4 0

3 years ago