ASAP TWENTY POINTS What type of image is formed by a mirror if m = -0.4?

Answer:

The time she takes to reach the water from when she jumps off the platform is 1.71 s

Explanation:

According to the equations of motion, we have;

v = u - g·t

v² = u² - 2·g·s

s₁ = u₁·t₁ + 1/2·g₁·t₁²

The given parameters are;

The height of the platform (assumption: above the water) = 10 m

The velocity with which she jumps, u = 3 m/s

The acceleration due to gravity, g = 9.81 m/s²

The height to which she jumps, s, is found as follows;

v² = u² - 2·g·s

At maximum height, v = 0, which gives;

0 = 3² - 2×9.81×s

2×9.81×s = 3² = 9

s = 9/(2×9.81) = 0.4587 m

s = 0.4587 m

The time to maximum height, t, is found as follows;

v = u - g·t

0 = 3 - 9.81×t

9.81×t = 3

t = 3/9.81 = 0.3058 s

The total distance, s₁ from maximum height to the water surface = s + 10 = 0.4587 + 10 = 10.4587 m = 10.46 m

The time to reach the water from maximum height, t₁, is found as follows;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

Where;

s₁ =  The total distance from maximum height to the water surface = 10.46 m

u₁ = The initial velocity, this time from the maximum height = 0 m/s

g₁ = The acceleration due to gravity, g (positive this time as the diver is accelerating down) = 9.81 m/s²

t₁ = The time to reach the water from maximum height

Substituting the values gives;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

10.46 = 0·t₁ + 1/2·9.81·t₁²

t₁²= 10.46/(1/2×9.81) = 2.13 s²

t₁ = √2.13  = 1.46 s

Total time = t₁ + t = 1.46 + 0.3058 = 1.7066 ≈ 1.71 s.

Therefore, the time she takes to reach the water from when she jumps off the platform = 1.71 s.

Answer:

usa

Explanation:

It isn't best to wear loose fitting clothing when exercising, as you may not feel too comfortable. It depends on the person. However there are a few advantages.

• Tight clothing may not be comfortable as well

• Looser clothing allows easy evaporation of sweat

Then again when it says " loose - fitting " it may mean not too baggy. Baggy clothing can have an impact on your physical activity.

Answer All of the above

For people on a p e x

Answer:CcCcccccc

Explanation:

Rfsgqh

Answer:

The correct option is;

a. 12.5 g

Explanation:

The given parameters are;

The initial mass of the radioactive substance = 200 g

The half life of the radioactive substance = 50 years

The time duration for the disintegration = 200 years

The formula for half life is given as follows;

[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}}[/tex]

Where:

N(t) = Quantity of the remaining substance

N₀ = Initial radioactive substance quantity  = 200 g

t = Time duration  = 200 years

[tex]t_{1/2}[/tex] = Half life of the radioactive substance  50 years

Therefore, we have;

[tex]N(t) =200 \times \left (\dfrac{1}{2} \right )^{\dfrac{200}{50} } =200 \times \left (\dfrac{1}{2} \right )^4 = 12.5 \ g[/tex]

Therefore, at the end of 200 years, the quantity left = 12.5 g.

Answer:

230 = x + 105

x= 125

Explanation:

v = v0 + at

Answer;

7.238°

Explanation

From question we know that the grating has 1,970 grooves per centimeter, we can convert to from (cm) to (nm) for unit consistency

The slit separation is expressed below

d=1cm/1970

d=0.0005076

=5076nm

Then the angle (in degrees) that the red light of wavelength 640 nm appear in first order can be calculated using expression below

Sin(x)= mλ/d

Where λ= wavelength=640 nm

d=slit separation

Sin(x)= mλ/d

Sin(x)=(1×640)/5076

=0.126

sin-1(0.126)

X= 7.238°

Therefore,the angle (in degrees) that the red light of wavelength 640 nm appear in first order is 7.238°

Answer:

Fnet = F√2

Fnet = kq²/r² √2

Explanation:

A exerts a force F on B, and C exerts an equal force F on B perpendicular to that.  The net force can be found with Pythagorean theorem:

Fnet = √(F² + F²)

Fnet = F√2

The force between two charges particles is:

F = k q₁ q₂ / r²

where

k is Coulomb's constant, q₁ and q₂ are the charges, and r is the distance between the charges.

If we say the charge of each particle is q, then:

F = kq²/r²

Substituting:

Fnet = kq²/r² √2

Answer:

Explanation:

Heat is transferred in the following ways listed below

1. Conduction(Through direct contact of particles )

2. Convection(Through motion of hot and cold liquid )

3. Radiation(Through electromagnetic waves Through the rising of a warm gas )

1. Conduction: This has to do with the transfer of heat from one medium to another having direct contact with each other, the medium can either be solid or liquids

2. Convection: Has to do with the transfer of heat energy via molecules of the liquids in motion with different or varying temperature gradients

3. Radiation: Mostly occurs in gases, it is the transfer of energy through waves

Answer:

a=F/m

a=12N/3kg  (here newton can be written as kgm/s^2 so kg will be cancelled)

a=4m/s^2

Explanation:

Answer:

1

Explanation:

Hydrogen is the first element in the periodic table so its atomic number is 1.

Explanation:

a) Acceleration is the slope of the velocity vs time graph.  When velocity vs time is a straight line, that means the acceleration is a constant.  F = ma, so the resultant force is also constant.

b) As air resistance increases, the acceleration begins to decrease.

c) A falling object stops accelerating when it reaches terminal velocity.

d) F = ma, so when the acceleration is 0, the resultant force is also 0.

Answer:

The distance Mr Franklin applied the force is 400 m

Explanation:

The efficiency of the machine = 80%

The force applied by the machine = 800 N

The distance over which the force is applied by the machine = 20 m

The force applied by Mr. Franklin = 50 N

The work done by the machine = 800 × 20 = 16000 J

The ideal work at 100% efficiency = X

80% of X = 16000 J

X = 16000 N/0.8 = 20,000 J

Therefore, we have have;

Work = Force × Distance;

20,000 J = 50 N × Distance Mr Franklin applied the force

Distance Mr Franklin applied the force = 20,000 J/(50 N) = 400 m

The distance Mr Franklin applied the force = 400 m.

Answer:

the awnser in 400m

Explanation:

did the test on edge 2020 and got it right

Answer:

17) a) 30 kg·m/s

b) 30 kg·m/s

c) 0.3 m/s.

18) 2.4 m/s

19) 360,000 N

The different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact

Explanation:

17) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the astronaut = 100 kg

v₁ = The initial velocity of the astronaut = 0 m/s

m₂ = The mass of the equipment box = 2.5 kg

v₂ = The initial velocity of the equipment box = 0 m/s

v₁' = The final velocity of the astronaut

v₂' = The final velocity of the equipment box = 12 m/s

The final momentum of the equipment box = Mass of the equipment box × Final velocity

a) The final momentum of the equipment box = 2.5 kg × 12 m/s = 30 kg·m/s

b) Given that the box and the astronaut will move in opposite directions, we have;

m₁·0 + m₂·0 = -m₁·v₁' + m₂·v₂'

m₁·v₁' = m₂·v₂'

Therefore, the momentum of the astronaut will be equal to the momentum of the equipment box = 30 kg·m/s

c)  The velocity of the astronaut is given by th following relation;

100×0 + 2.5×0 = -100×v₁' + 2.5×12

100×v₁' = 2.5×12

v₁' = 2.5×12/100 = 30/100 = 0.3 m/s

The final velocity of the astronaut = 0.3 m/s.

18) By conservation of linear momentum principle, we have;

m₁·v₁ + m₂·v₂ = m₁·v₁' + m₂·v₂'

Where;

m₁ = The mass of the railway truck= 4000 kg

v₁ = The initial velocity of the railway truck= 8 m/s

m₂ = The mass of the stationary truck = 6000 kg

v₂ = The initial velocity of the stationary truck = 0 m/s

v₁' = The velocity of the two trucks immediately after collision

Therefore, we have;

4000 kg × 6 m/s + 6000 × 0 = (6000 + 4000) × v₁' = 10,000·v₁'

24,000 kg·m/s = 10,000·v₁'

v₁' = 24,000/10,000 = 2.4 m/s

The velocity of the two trucks immediately after collision is = 2.4 m/s

19) The change in kinetic energy of the car due to the collision = 1/2·m·(v₂² - v₁²)

The initial velocity of the car, v₁ = 12 m/s

The final velocity, v₂ = 0 m/s

The mass of the car, m= 600 kg

The time in which the car is brought to rest = 2 seconds

Initial time at point of collision, t₁ = 0 s

Time after collision, t₂ = 0.02 s

By Newton's second law of motion, we have

The force F acting on the car = Rate of change in momentum produced by the force

F = m × dv/dt

Force  = m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.02 - 0) = -360,000 kg·m/s²

The force acting on the car  is equal and opposite to the force of the car =  360,000 N

b) For the different make of the car, we have;

m × (v₂ - v₁)/(t₂ - t₁) = 600×(0-12)/(0.25 - 0) = -28,800 kg·m/s². = -28,800 N

Therefore, the different make of  car is safer because the force acting on it  is 28,800 N, resulting much less impact.

Answer:

True

Explanation:

Thats is true since it cannot be a vector because speed only gives a magnitude, not a direction as well.

Answer:

pull

Explanation:

because when you push there is one component of force that adds to tge weight of body and hence there is more friction. Whwn you pull the vertical component of force is against the weight of body and hence friction is low.

Answer:

1.05×10⁻⁴ m²

Explanation:

ΔA = 2 A₀ α ΔT,

where ΔA is the change in area,

A₀ is the initial area,

α is the linear expansion coefficient,

and ΔT is the change in temperature.

A₀ = π (0.20 m / 2)² = 0.0314 m².

For steel, α = 13×10⁻⁶ /°C.

ΔT = 150°C − 22°C = 128°C.

ΔA = 2 (0.0314 m²) (13×10⁻⁶ /°C) (128°C)

ΔA = 1.05×10⁻⁴ m²

Answer:

The tension in the rod as the ball moves through the bottom circle is 9.8 N

Explanation:

When the ball is released from rest, the centripetal force equals the weight of the ball. So mv²/r = mg where m = mass of ball = 0.5 kg, v = speed of ball, r = radius of vertical circle = length of rod = 0.5 m and g = acceleration due to gravity = 9.8 m/s²

v = √gr = √9.8 m/s² × 0.5 m = √4.9 = 2.21 m/s

Now at the bottom of the circle T - mg = mv²/r where T = tension in the rod

T = m(g + v²/r)

= m(g + (√gr)²/r)

= m(g+ gr/r)

= m(g + g)

= 2mg

= 2 × 0.5 kg × 9.8 m/s²

= 9.8 N

So, the tension in the rod as the ball moves through the bottom circle is 9.8 N

Answer:

D

Explanation:

because light has no space nor mass

Answer:

F = 0.408 N

Explanation:

It is given that,

Weight of a wooden block, W = 8 N

Weight, W = mg

m is mass of wooden block

[tex]m=\dfrac{W}{g}\\\\m=\dfrac{8\ N}{9.8\ m/s^2}\\\\m=0.816\ kg[/tex]

Acceleration of the block, a = 0.5 m/s²

Force, F = ma

[tex]F=0.816\ kg\times 0.5\ m/s^2\\\\F=0.408\ N[/tex]

So, the magnitude of force applied to the wooden block is 0.408 N.

Answer:

C. Walk four times per week

Explanation:

If she wants to increase her time then, she has to walk four times per week.

The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.

The mathematical expression for speed is given by

speed = total distance /Total time

As given in the problem Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She must walk four times a week if she wants to extend her time.

Thus, the correct answer is option C.

Learn more about speed from here, refer to the link;

brainly.com/question/7359669

#SPJ2

The question is incomplete, the complete question is,

Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time. What should she do?

A. Walk at 4.5 miles per hour.

B. Walk for 50 minutes.

C. Walk four times per week.

D. Walk up and down more hills.

Answer:

healthy diet

Explanation:

Exercise and a healthy diet are the two things people do to stay healthy

Answer:

SI units are the physical units of measurement. SI units include kilogram, meter, second, ampere, kelvin, candela, and mole etcetera.

SI units are very important for daily life while measuring daily life commodities, such as:

Without SI units, it would be difficult to meausre the amount of object required or any other measurement object.

Answer:

The spring was compressed the following amount:

[tex]\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]

Explanation:

Use conservation of energy between initial and final state, considering that the surface id frictionless, and there is no loss in thermal energy due to friction. the total initial energy is the potential energy of the compressed spring (by an amount [tex]\Delta x[/tex]), and the total final energy is the addition of the kinetic energies of both masses:

[tex]E_i=\frac{1}{2} k\,(\Delta x)^2\\\\E_f=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2[/tex]

[tex]E_i=E_f\\[/tex]

[tex]\frac{1}{2} k\,(\Delta x)^2=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2\\k\,(\Delta x)^2=m_1\,v_1^2+ m_2\,v_2^2\\(\Delta x)^2=\frac{m_1\,v_1^2+ m_2\,v_2^2}{k} \\\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]

Answer:

velocity

Explanation:

Unbalanced forces on an object cause it to accelerate.  Acceleration is a change in velocity over time.

Answer:

a

Explanation:

none

Answer:

Parachutes

Explanation:

Your parachute allows you to descend more slowly because it lowers terminal velocity by increasing your air resistance. Most parachutes are designed to create a large amount of drag and allow you to land at a safe, low speed.

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Answer:

236.8 cm

Explanation:

1 yr = 365 days = (365×24×60×60) secs

= 32 × 10^6

distace = velocity × time

= 7.4 × 10^-6 × 32 × 10^6

= 236.8 cm

The glacier will move 976.8 cm when it advances at 7.4 7.4×10⁻⁶ cm/s in 4.2 y

From the question above when we talk about how far, is still the same as distance.

Applying the equation of velocity,

V = d/t................... Equation 1

Where V = velocity, d = distance, t = time

make d the subject of equation 1

d = Vt................ Equation 2

From the question,

Given: V = 7.4×10⁻⁶ cm/s, t = 4.2 year = (4.2×3.154×10⁷) seconds = 1.32×10⁸ seconds

Substitute these values into equation 2

d = (7.4×10⁻⁶)(1.32×10⁸)

d = 9.768×10² cm

d = 976.8 cm

Hence the glacier will advances 976.8 cm

Learn more about distance here: https://brainly.com/question/22491931

Answer: ear phones

Explanation:

You can physically hold ear phones, but you can't hold music, sunlight, or heat.

Answer:

Ra, 88

Ru, 44

Cr, 24

Explanation:

i

the remaining mass number is 224(228 - 4), and it's atomic number is 88(90 - 2). The element is Radium, Ra

ii

the remaining mass number is 98(98 - 0), and it's atomic number is 44(45 - 1). The element is Ruthenium, Ru

iii

The remaining mass number is 52(52 - 0), and it's atomic number is 24(23 - -1). The element is Chromium, Cr

Answer:  A Battery contains chemical energy which transfers electrical energy into the phone, powering it and also transferring Light energy, Sound energy and Heat energy.

Explanation: