pls help me i need both answers pls help me this is being timed.

Answer:

(a) -6.67 [tex]m/s^2[/tex]

(b) 0.68

Explanation:

Given that the mass of the truck, [tex]m_1=8000[/tex] kg.

Mass of the package, [tex]m_2=3000[/tex] kg.

As the package does not slide, so the acceleration of both, truck as well as the package, is the same.

Let [tex]a\;\; m/s^2[/tex] is the acceleration of the combined mass, m.

[tex]m=m_1+m_2= 8000+3000=11000[/tex] kg.

The initial velocity of the combined mass, u= 20 m/s.

Time required to stop, t=3 seconds.

Final velocity, v=0.

Displacement traveled, s=50 m.

(a) As  [tex]a=\frac {v-u}{t}[/tex]

[tex]\Rightarrow a=\frac{0-20}{3}=-\frac{20}{3} =6.67 m/s^2[/tex]

Hence the acceleration of the truck is [tex]-6.67 m/s^2.[/tex]

(b) Now, [tex]a=-6.67 m/s^2[/tex] is the acceleration of the package, this acceleration is due the frictional force, f.

Due to inertia, on application of break, the package have tendency to slide to left (in  the direction of velocity). But the package does not slides, this is only due to the frictional force, f, which acts in the right direction ( opposite to the direction of velocity).

So, the magnitude of frictional force required on [tex]m_2[/tex]  to avoid slide is

[tex]f=|m_2a|=\frac{20}{3}m_2\times(i)[/tex]

Now, let \mu be the minimum coefficient of the friction, so

The force due to friction, [tex]f_r= \mu N[/tex],

where [tex]\mu N[/tex] is the normal reaction.

[tex]N=m_2g[/tex], where g is the acceleration due to gravity.

So, [tex]f_r=\mu m_2g\cdots(ii)[/tex]

To avoid slide, [tex]f_r\geq f[/tex]

[tex]\Rightarrow \mu m_2g\geq\frac{20}{3}m_2[/tex] [from (i)and (ii)]

[tex]\Rightarrow \mu\geq \frac{20}{3\times 9.81}[/tex]    [tex][ as \;g=9.81 m/s^2][/tex]

[tex]\Rightarrow \mu \geq 0.68[/tex]

Hence, the minimum value of coefficient of friction between packages and the truck os 0.68.

Answer:

Hh

Explanation:

Ghhhh

Answer:

Health relates to science because

in science you study, research, and knowledge in this case, health science, which helps you under stand more about how humans and animals function. And Physical education relates to science because , you study the way of human movement, think of push-ups as a example.

I hope I helped U ´꓃ ` U

Answer:

[tex]\boxed {\boxed {\sf 2 \ m/s^2}}[/tex]

Explanation:

Acceleration can be found by dividing the change in velocity by the time.

[tex]a=\frac{\Delta v}{t}[/tex]

The time is 1.25 seconds.  The change in velocity is the difference between the initial velocity and the final velocity.

[tex]\Delta v= 2.5 \ m/s\\t=1.25 \ s[/tex]

Substitute the values into the formula.

[tex]a=\frac{2.5 \ m/s}{1.25 \ s}[/tex]

Divide.

[tex]a=2 \ m/s^2[/tex]

The sprinter's average acceleration is 2 meters per second squared.

Answer: 2 m/s^2

Explanation: Hope this helps :)

Answer:

because the gravitational pull is maximum at the poles and decreases as it comes down toward the equator.

Answer:

V = I×R

where -

V = potential difference across

I = current flowing in the circuit

R = Equivalent Resistance in the circuit

Answer:

Answer:

V = I×R

where -

V = potential difference across

I = current flowing in the circuit

R = Equivalent Resistance in the circuit

Explanation:

it would be on the ground

Answer:

This is what I got the teacher hasn’t graded it yet so sorry if it’s not right

Explanation:

Answer:

the density is 0.301 :)

‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎‎1500 kpm

Answer:

The type of mechanical energy that is possessed due to the virtue of motion or state of a body is known as potential energy.

Its formula: PE= mgh

Its SI unit is joule.

Hope it helps you..

Answer:

1) 2197.44 J

2) 0 J

3) 2197.44 J = Constant

4) 2197.44 J

5) Approximately 8.86 m/s

Explanation:

The given parameters are;

The mass of the diver, m = 56 kg

The height of the cliff, h = 4.0 m

The speed with which the diver is moving, vₓ = 8.0 m/s

The gravitational potential energy = Mass, m × Height of the cliff, h × Acceleration due to gravity, g

1) Her gravitational potential energy = 56 × 4.0 × 9.81 = 2197.44 J

2) The kinetic energy = 1/2·m·u²

Where;

u = Her initial velocity = 0 when she just leaves the cliff

Therefore;

Her kinetic energy when she just leaves the cliff = 1/2 × 56 × 0² = 0 J

3) The total mechanical energy = Kinetic energy + Potential energy

The total mechanical energy is constant

Her total mechanical energy relative to the water surface when she leaves the cliff = Her gravitational potential energy = 2197.44 J = Constant

4) Her total mechanical energy relative to the water surface just before she enters the water = 2197.44 J

5) The speed with which she enters the water, v, is given from, v² = u² + 2·g·h

Where;

u = The initial velocity at the top of the cliff before she jumps= 0 m/s

∴ v² = 0² + 2 × 9.81 × 4 = 78.48

v = √78.48 ≈ 8.86 m/s

The speed with which she enters the water, v ≈ 8.86 m/s

1) Her gravitational potential energy relative to the water surface when she leaves the cliff is; GPE(leaves cliff) = 2195.2 J

2) Her kinetic energy when she leaves the cliff is; KE = 0J

3) Her total mechanical energy relative to the water surface when she leaves the cliff is; ME_total = 2195.2 J

4) Her total mechanical energy relative to the water surface just before she enters the water is; ME_total = 2195.2 J

5) The speed at which she enters the water is; v = 8.85 m/s

We are given;

Mass of the diver; m = 56 kg

Height of the cliff; h = 4 m

Speed at which she is moving; vₓ = 8 m/s

1) Formula for gravitational potential energy is;

GPE = mgh

where;

m is mass

g is acceleration due to gravity

h is height

Thus;

GPE = 56 × 4 × 9.8

GPE(leaves cliff) = 2195.2 J

2) The formula for kinetic energy when she leaves the cliff is;

KE = ¹/₂mu²

Where;

m is mass

u = initial velocity = 0 m/s

Thus;

KE = ¹/₂ × 56 × 0²

KE(leaves cliff) = 0 J

3) The total mechanical energy relative to the water surface when she leaves the cliffis;

ME_total = GPE(leaves cliff) + KE(leaves cliff)

Thus;

ME_total = 2195.2 + 0

ME_total = 2195.2 J  

4) Her total mechanical energy relative to the water surface just before she enters the water is same as that when she leaves the cliff = 2195.2 J

5) The speed with which she enters the water, v, is gotten from newtons third equation of motion;

v² = u² + 2gh

Thus;

v² = 0² + (2 × 9.8 × 4)

v² = 78.4

v = √78.4

v = 8.85 m/s

Read more at; https://brainly.com/question/25708521

Answer:

Explanation:

KHAN ACADEMY

The correct free body diagram is option (B). There will only be two forces acting on cheese B.

By representing the tensional forces by the ropes 1 and 2 as [tex]F_{T1}[/tex] and [tex]F_{T2}[/tex] respectively, the correct free body diagram will be option B.

Learn more about free body diagrams here:

https://brainly.in/question/12953409

Answer:

tura paulo

Explanation:

sry if im wrong ;)

Answer:

Explanation:

3. Newton’s third law explains how every action has an equal but opposite reaction, meaning that forces comes in pairs. While the locomotive’s wheels are pushing back against the ground as the action force, the ground is producing a reaction force towards the locomotive, propelling it forward. Another pair of forces that act on the locomotive is gravity and normal force. While gravity is pulling the locomotive towards the ground, the normal force the ground exerts on the locomotive is why the locomotive doesn’t fall through the ground.

4. The force of Earth’s gravity on the Sun is weaker than the force of the Sun’s gravity on Earth. The Sun’s attraction  affects the motion of Earth more than the Earth’s attraction affects the Sun’s motion because according to  Newton’s second law, force has mass as one of its factors. The Sun has a significantly higher mass than Earth,  meaning that its force of gravity would also be significantly higher. Newton’s third law is why the Earth doesn’t get  marginally closer to the Sun, stating that every action has an equal and opposite reaction. As the Sun is pulling  Earth towards itself, Earth is pulling away from the Sun.

Answer:

it was given the name Newton (N). from this, the derived unit of energy (or work) is defined ,as the work produced when the unit of force causes a displacement equal to the unit of length of its point of application along its direction . It was given the name Joule (J).

Explanation:

Answer:

D. The skier's weight, the force of friction between the skis and snow,

and the force of air resistance

Explanation:

If two objects, such as the the skier, and skies undergo a fast velocity downward, the net force is the total force or newtons which are all components of weight as apparent to mass and gravity, friction, which is the contact force of the skis on the snow, and air resistance which limits the air resistance is the opposite force acting on the object I'm the air relative to the density of air, cross sectional area of the object, the coefficient of drag which is based on the density of the object, it's area, and dynamic air pressure.

Answer:

9.8 m/s/s

Explanation:

The horizontal velocity of a projectile is constant (a never changing in value), There is a vertical acceleration caused by gravity; its valueis 9.8 m/s/s, down, The vertical velocity of a projectile changes by 9.8 m/s each second, Thehorizontal motion of a projectile is independent of its vertical motion.

Answer:

the horizontal component of the velocity, however, retains its initial value v0x=+115 m/s throughout the entire descent.

Explanation:

since the plane also travels at a constant horizontal velocity of +115 m/s, it remains directly above the falling package.

Explanation:

HERE you go. hope this helps.

Answer: a piece of iron near a magnet

Explanation:

Answer:

3 a is the ans i think so ....

Answer:

I got you.. i'm in middle school and had that same question.

Explanation:

Refer to the diagram shown below.

The vertical distance traveled is

s = 25 m

The initial vertical launch velocity is zero.

Therefore

s = (1/2)*g*t²

where g = 9.8 m/s²

t = the time of flight, s

That is,

0.5*9.8*t² = 25

t² = 25/4.9 = 5.102

t = 2.26 s

Answer: 2.26 s

Answer:

Negatively charged, to positively charged parts

Explanation:

Electrons are negative, negative is attracted to positive.

Answer:

An element's valence electron tells us about its ability to react and not react. More rules to this, but that's the gist of it. it also helps us form bonds

Explanation:

Valence electrons are used by an element for bonding and ionization, contributing to the element's chemical reactivity and behavior.

Valence electrons also play a vital role in ionization, which refers to the process of gaining or losing electrons to form ions. Elements tend to gain or lose electrons in order to achieve a stable electron configuration, typically by acquiring a full valence shell.

Metals, located on the left side of the periodic table, have fewer valence electrons, often one or two, and tend to lose them to form positive ions (cations). This characteristic makes them good conductors of electricity.

Nonmetals, located on the right side of the periodic table, have a nearly full valence shell and tend to gain electrons to achieve a stable configuration, forming negative ions (anions). Nonmetals generally do not conduct electricity as well as metals.

In summary, valence electrons are used by an element for bonding, where they participate in the formation of covalent and ionic bonds, and for ionization, where they are gained or lost to form ions and achieve a stable electron configuration.

To know more about electrons here

https://brainly.com/question/12001116

#SPJ6