A car completes a journey in 2 hours. Its average speed over this journey was 45 mph. Calculate the distance travelled by the car in miles.

Explanation:

The vertical component the velocity of the projectile is 15 m/s x sin 30 = 7.5 m/s.

The body is accelarating downwards at 10 m/s^2.

This means that every second its upward velocity reduces by 10 m/s.

So if the body is travelling upwards at 7.5 m/s then how long does it take for the velocity to become 0?

(7.5 m/s) / (10 m/s^2) = 0.75 s

Answer:

True :p

Explanation:

Carbohydrates are foods that get converted into glucose.

Answer:

 t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex],  v_r = 1 m/s       t ’= 547.19 s

Explanation:

This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.

By the time the boat goes up the river

        v_b - v_r = d / t

By the time the boat goes down the river

        v_b + v_r = d '/ t'

let's subtract the equations

       2 v_r = d ’/ t’ - d / t

       d ’/ t’ = 2v_r + d / t

       [tex]t' = \frac{d'}{ \frac{d}{t}+ 2 v_r }[/tex]

In the exercise they tell us

         d = 1.22 +1.45 = 2.67 km= 2.67 10³ m

         d ’= 1.45 km= 1.45 1.³ m

at time t = 69.1 min (60 s / 1min) = 4146 s

the speed of river is v_r

      t ’= [tex]\frac{1.45 \ 10^3}{ \frac{ 2670}{4146} \ + 2 \ v_r}[/tex]

      t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex]

In order to complete the calculation, we must assume a river speed

          v_r = 1 m / s

let's calculate

      t ’= [tex]\frac{ 1450}{ 0.6499 + 2 \ 1}[/tex]

      t ’= 547.19 s

Answer:

Ultraviolet rays from sun are very harmful from skin and can cause sunburn and skin diseases especially ultraviolet B rays. A sunscreen  lotion act as a protection barrier on the skin that restrict the direct contact of UV rays with skin and filter the harmful rays to enter the skin.

Radiotherapy is a medical therapy use to treat cancer. Radiotherapy commonly uses x-rays and gamma rays because they are high-energy particles or waves that kills or destroys the cancer cells.

Sunscreen lotion is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.

The sun reaches us from outer space brings ultraviolet rays to us. Ultraviolet rays are known to have some damaging effects on the skin. One way to protect our skin from this damaging ultraviolet rays is to use sunscreen lotion which is able to filter this damaging ultraviolet radiation and prevent it from damaging the skin.

X-rays and gamma rays are used in radiotherapy because they are light energy rays which are able to penetrate and destroy malignant cells in the body.

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Answer:

the speed and aceleration of the ping pong ball is greater than that of the bowling ball.

Explanation:

We can analyze this exercise from several points of view, if we use Newton's second law

Bowling ball

           F = M a₁

pingpongg ball

           F = m a₂

as the forces the same

          M a₁ = m a₂

          a₂ = [tex]\frac{M}{m}[/tex] a₁

Since the mass of the bowling ball is much greater than the ping pong ball,

          a₂ »a₁

so the acceleration of the ping pong ball is much greater than the acceleration of the bowling ball.

If we use the relationship of momentum and momentum, assuming that the time for the two cases is the same and that both start from rest

Bowling ball

           I = F t = Δp

           I = M (v₁ - v₀)

Ping pong ball

           I = F t = Δp

           I = m (v₂ -v₀)

the impulse itself

          M v₁ = m v₂

          v₂ = [tex]\frac{M }{ m}[/tex] v₁

so we conclude that the speed of the ping pong ball is much greater than the speed of the bowling ball.

In conclusion the speed and aceleration of the ping pong ball is greater than that of the bowling ball.

Answer:

I think that this ans may help you

Answer: Option A;  9.8 m/s^2

Explanation:

When an object is in the air, and there is no air resistance acting on the object, the only force that will act on the object is the gravitational force (on the vertical axis).

Then, if the only force acting on the object is the gravitational force, the acceleration of the object will be equal to the gravitational acceleration.

We know that the gravitational acceleration is equal to:

g = 9.8m/s^2

Then the acceleration on the vertical axis will be equal to:

a(t) = 9.8m/s^2

The correct option is the first one:

A. 9.8 m/s^2

Answer: reduced by 1/4

Explanation:

The force will be reduced by 1/4. Try plugging in 2r, then squaring it. You will get 4r^2, which is essentially dividing the force by 4

Answer:

Explanation:

initial velocity u = 0

final velocity v = 11.3 m /s

distance covered s = 12.8 m

v² = u² + 2 a s

11.3² = 0 + 2 x a x 12.8

a = 4.99 m /s²

again ,

v = u + a t

11.3 = 0 + 4.99 t

t = 2.26 s .

Rest of the sprint will be covered with uniform velocity .

Distance covered = 100 - 12.8 = 87.2 m

speed = 11.3 m /s

time taken = 87.2 / 11.3 = 7.7 s

Total time of 100 m sprint = 7.7 + 2.26 = 9.96 m .

b )

Let the time taken to reach the top speed be t .

acceleration a = 11.3 / t

distance covered s = 1/2 a t²

= .5 x (11.3 / t) x t²

= 5.65 t

Rest of the distance = 100 - 5.65 t

time taken to cover rest of the distance = (100 - 5.65 t ) / 11.3

Total time =  (100 - 5.65 t  / 11.3 ) + t = 9.75

100 - 5.65 t + 11.3 t = 11.3 x 9.75

100 + 5.65 t = 110.175

5.65 t = 10.175

t = 1.8

acceleration a = 11.3 / t

= 11.3 / 1.8

= 6.278 m /s²

distance covered in 1.8 s

s = 1/2 a t²

= .5 x 6.278 x 1.8²

= 10.17 m .

Frequency = (speed) / (wavelength)

Frequency = (3 x 10⁸ m/s) / (124 x 10⁻⁹ m)

Frequency = 2.42 x 10¹⁵ Hz

Answer: 3. To give the object a negative charge we must give it more electrons, and this will increase its mass.

Explanation:

Suppose we have an object and we negatively charge it.

Then we are "adding" N electrons to the object.

Remember that the mass of an electron is:

m = 9.11*10^(-31) kg

Then if we add N electrons to an object of mass M, the new mass of the object will be:

Mass = M + N*9.11*10^(-31) kg

So we will have an (almost negligible) increase of the mass of the object.

(Something similar can happen if the object is positively charged, where we remove electrons, then the mass of the object decreases)

Then the correct option is:

3. To give the object a negative charge we must give it more electrons, and this will increase its mass.

Answer:

Explanation:

Maximum height reached = 90.6 m . Range = 48.5 m

. Let u be the initial velocity at angle α .

Horizontal range is covered by horizontal component of u .

Vertical height is achieved by vertical component

v² = u² sin² α - 2gh , t is time taken to attain maximum height .

0 = u² sin² α - 2 x 90.6 x 9.8  

u² sin² α = 2 x 887.88  -------( 1 )

Range R = u² sin2α / g

48.5 = 2 u² sinα . cos α / 9.8

u² sinα . cos α = 237.65 -----------------------------  ( 2 )

( 1 ) / ( 2 )

Tan α = 2 x 887.88 / 237.65 = 7.47

α = 82⁰

u² sin² α = 2 x 887.88

u² sin² 82 = 2 x 887.88

u² = 1812

u = 42.56  m /s

Answer:

32kg = 313.6N

82kg = 803.6N

1000kg = 9800N

524N = 53.47kg

441N = 45kg

51N = 5.20kg

for the box diagram the weight of the 15kg box is 147N

the net force will be equal to zero because the box is motionless

Fg goes downward arrow of box 147N

Fnorm goes upward arrow of box 147N

Answer:

True

Explanation:

The kinetic energy of an object is the energy that it possesses due to its movement or motion.

True, the amount of kinetic energy an object has depends on its mass and its speed.

The kinetic energy of a moving object is directly proportional to the square of its velocity and directly proportional to its mass.

Answer:

One sphere obtains a positive charge, while the other obtains a negative charge.

Explanation:

When the negatively-charged rod is brought close to the two neutral spheres in contact with each other, the electrons in both spheres are repelled away from the rod and thus those electrons move into the second sphere farther away from the rod.

The first sphere is now short of electrons.

When the spheres are separated, the first sphere which is short of electrons now carries a net positive charge, while the other sphere which has excess electrons now carries a net negative charge.

Solution :

Length of the plastic rod , L = 1.6 m

Total charge on the plastic rod , Q = [tex]$-9 \times 10^{-8}$[/tex] C

The rod is divided into 8 pieces.

a). The length of the 8 pieces is , [tex]$l=\frac{L}{8}$[/tex]

                                                         [tex]$=\frac{1.6}{8}$[/tex]

                                                         = 0.2 m

b). Location of the center of the piece number 5 is given as : 0 m, -0.09375 m, 0 m.

c). The charge q on the piece number 5 is given as

[tex]$q=\frac{Q}{L}\times l$[/tex]

[tex]$q=\frac{-9 \times 10^{-8}}{1.6}\times0.2$[/tex]

 = [tex]$-1.125 \times 10^{-8}$[/tex] C

d). WE approximate that piece 5 as a point charge and we need to find out the field at point A(0.7 m, 0, 0) only due to the charge.

We know,  the Coulombs force constant, k = [tex]$8.99 \times 10^9 \ N.m^2/C^2$[/tex]

So the X component of the electric field at the point A  is given as

[tex]$E_x = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \cos \frac{187.628}{0.70625}$[/tex]

     = -126.15 N/C

The Y component of the electric field at the point A is

[tex]$E_y = 8.99 \times 10^9 \times 1 \times 10^{-8} \ \sin \frac{187.628}{0.70625}$[/tex]

    = -16.93 N/C

Now since the rod and the point A is in the x - y plane, the z component of the field at point A due to the piece 5 will be zero.

∴ [tex]$E_z=0$[/tex]

Thus, [tex]$E= <-126.15,-16.93,0>$[/tex]

Answer:

Mary will have to wait for 63.2 seconds

Explanation:

Time required for the apple to drop from a height of 17.0 m above the ground to 1.65 m above the ground is given by the formula below:

t = √2h/g  where h is height through which the object falls, g is acceleration due to gravity

h = 17.0 - 1.65 = 15.35 m

g = 9.8 m/s²

t = √(2 * 15.35/9.8)

t = 1.77 s or approximately 1.8 s

Time taken for bill to get to the point below Mary's window is given below;

time taken = distance/velocity

distance = 130 m; velocity = 2.0 m/s

time taken by Bill = 130/2.0 = 65 s

Therefore, Mary will have to wait for (65 - 1.8) s = 63.2 seconds

Mary should have to wait for 63.2 seconds

t = √2h/g

here h is height via which the object falls,

g represent acceleration due to gravity

So,

h = 17.0 - 1.65

= 15.35 m

And,

g = 9.8 m/s²

Now

t = √(2 * 15.35/9.8)

t = 1.77 s or approximately 1.8 s

Now the time taken should be

= 130/2.0

= 65 s

So,

= (65 - 1.8) s

= 63.2 seconds

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Answer: [tex]p_{x}=[/tex] 0.0135814 kg.m/s

              [tex]p_{y}=-0.000219[/tex] kg.m/s

Explanation: When an object with mass is in motion, we say the object has momentum (p). Momentum is dependent on mass and velocity:

p = m.v

The total momentum of Bryce's mice is calculated as

x-axis

[tex]p_{x}=\Sigma m.v_{x}[/tex]

[tex]p_{x}=[(0.0213)(0.675)+(0.0165)(-0.249)+(0.0185)(0.395)+(0.0193)(-0.207)][/tex]

[tex]p_{x}=[/tex] 0.0135814

At the x-axis, total momentum of Bryce's mice is 0.0135814 kg.m/s.

y-axis

[tex]p_{y}=\Sigma m.v_{y}[/tex]

[tex]p_{y}=[(0.0213)(-0.417)+(0.0165)(-0.809)+(0.0185)(0.953)+(0.0193)(0.227)][/tex]

[tex]p_{y}=-0.000219[/tex]

At the y-axis, total momentum of Bryce's mice is -0.000219 kg.m/s.

Answer:

In my physics class, something that helps connect better with kids is keeping connected with them always make sure to ask if they understand what you're teaching if they are following because sometimes most kids are to afraid to admit that they are lost, another way to connect with kids is maybe posting surveys to be able to check in with each student especially during this hard times :)

Explanation:

1. start with fun activities.

2. Encourage single-tasking.

3. Designate a learning playing field.

Answer:

Explanation:

When two north magnetic poles are  placed close to each other , they will repel each other . If distance between them is increased due to mutual repulsion from x to 12 x , work is done by the magnetic field . This results in decrease of magnetic field energy .

Hence , when the distance between the poles becomes 12x from x , the magnitude of the field energy between them decreases .

Answer:

the moment of inertia is 4.5 × 10⁻⁵ kg.m²  

Explanation:

Given that;

point mass m = 0.005 g = ( 0.005 / 1000 ) = 5 × 10⁻⁶ kg

perpendicular distance r = 3m

We know that a point mass doesn't have a moment of inertia around its own axis but, but using the parallel axis theorem, a moment of inertia around a distant axis of rotation can be determined using;

[tex]I_{}[/tex] = mr²

so we substitute

[tex]I_{}[/tex] = (5 × 10⁻⁶ kg) × (3 m)²

[tex]I_{}[/tex] = (5 × 10⁻⁶ kg) × 9 m²

[tex]I_{}[/tex]  = 4.5 × 10⁻⁵ kg.m²  

Therefore; the moment of inertia is 4.5 × 10⁻⁵ kg.m²  

The moment of inertia of given point mass is 4.5 × 10⁻⁵ kgm² at a perpendicular distance of 3 m.

The moment of inertia of given point mass can be determined by,

[tex]I = mr^2[/tex]

Where,

[tex]I[/tex]- moment of inertia

[tex]m[/tex]- mass = 0.005 g = ( 0.005 / 1000 ) = 5 × 10⁻⁶ kg

[tex]r[/tex] - perpendicular distance = 3 m

Put the values in the formula,

[tex]I = (5 \times 10^{-6}{\rm \ kg}) \times (3 {\rm \ m})^2\\\\I = 5 \times 10^{-6}{\rm \ kg} \times 9 {\rm \ m}\\\\I = 4.5 \times 10^{-5} kgm^2[/tex]

Therefore; the moment of inertia of given point mass is 4.5 × 10⁻⁵ kgm².

To know more about moment of inertia,

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Answer:

The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time. In this example, distance is in metres (m) and time is in seconds (s), so the units will be in metres per second (m/s).

For answering this question,let us assume that a person is pushing against the walls,so now:

Which object exerts the action force?

Which object exerts the reaction force?

In what direction does the action force push?

In what direction does the reaction force push?

The answer varies from different scenarios.

Answer:

diver, diving board, down, and up.

Explanation:

Explanation:

O + 6V = 9V, so O = 3V

P = 9V as it is parallel to the 9V power supply.

Answer:

weight

Explanation:

weight is the pull of gravity so its a force !!

Answer:Purpose of Cloning

A forensic image of a hard drive captures everything on the hard drive, from the physical beginning to the physical end. ... Hard drives are susceptible to failure. Having two clones gives an investigator one to examine and one to fall back on.Therapeutic cloning involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease.

Explanation:

hope this helps have a nice night lo❤️❤️❤️l

Cloning

Cloning is defined as a technique used by scientists to make exact genetic copies of living things. Genes, cells, tissues, and even whole animals can all be cloned.

Everything on the hard drive is captured by the forensic image. Hard drives can be a failure. If possible, the original drive should be preserved in a safe place and only brought out to reimage if needed. Ideally, all examinations are done on a clone as opposed to the original.

One of the cloning types is Therapeutic cloning which involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease.

To know more about cloning, follow the link given below.

https://brainly.com/question/25737082.

Answer:

the power that can be generated by the river is 117.6 MW

Explanation:

Given that;

Volume flow rate of river v = 240 m³/s

Height above the lake surface a h = 50 m

Amount of power can be generated from this river water after the dam is filled = ?

Now the collected water in the dam contains potential energy which is used for the power generation,

hence, total mechanical energy is due to potential energy alone.

[tex]E_{mech}[/tex] = m(gh)

first we determine the mass flow rate of the fluid m

m = p×v

where p is density ( 1000 kg/m³

so we substitute

m = 1000kg/m³ × 240 m³/s

m = 240000 kg/s

so we plug in our values into ( [tex]E_{mech}[/tex] = m(gh) kJ/kg )

[tex]E_{mech}[/tex] = 240000 × 9.8 × 50

[tex]E_{mech}[/tex] = 117600000 W

[tex]E_{mech}[/tex] = 117.6 MW

Therefore, the power that can be generated by the river is 117.6 MW