Find the speed of the mobile after 4 seconds

Answer:

conduction

Explanation:

conduction is the movement of heat from one point to another on a metal.

Hope it helps.

Answer:

The total frictional force equals 60 N

Explanation:

We know that F - f = ma where F is the applied force, f is the frictional force, m the mass of the object and a its acceleration.

Now, since the cart moves with constant velocity, its acceleration is zero. So, a = 0.

So F - f = ma

F - f = m(0) = 0

F - f = 0

So, F = f

From the above, we see that the frictional force equals the applied force which is equal to 60 N.

So, f the total frictional force equals 60 N

Answer:

True

Explanation:

Newtons Law states that "When a net force acts on a body, it produces acceleration in the body in the direction of the net force. The magnitude of acceleration is directly proportional to the net force and inversely proportional to its mass."

So, it's mathematical form is

=> a ∝ F     (1)

=> a ∝ [tex]\frac{1}{m}[/tex]

Combining the proportionality

=> a ∝ [tex]\frac{F}{m}[/tex]

=> F ∝ ma

Using k as proportionality constant.

=> F = kma

Here k = 1

=> F = ma (Proved)

Answer:

200 Watts.

Explanation:

Power is defines as the amount of work expended per unit time. Mathematically, it is expressed as Power = Workdone/Time

Given parameters

Energy used up 100Joules

Distance moved by brick = 1 meters

Time taken by the machine = 0.5 secs

Power can also be written as Energy/Time

Required

We need to calculate the amount of power used up.

Power = 100J/0.5s

Power = 100/(1/2)

Power = 100 * 2/1

Power = 200Watts.

This shows that the machine would expend 200Watts of power

Answer:

The patient is suffering from protein deficiency

Explanation:

Protein deficiency is characterized by symptoms such as stunted growth; skin, nail and hair problems, loss of muscle mass, and in extreme cases, kwashiorkor.

Deficiency in protein is usually corrected by taking foods rich in protein such as egg's albumin, milk, pulses, beans, etc; hence the advice of the doctor.

Answer:

He should aim it at the monkey

Explanation:

The question is related to projectile motion of an arrow from a bow such that the arrow is able to reach a specific target

Therefore, since the monkey is going to drop from the tree the instant the person launches the food, then for the monkey to be able reach the food, we have;

Final level position of the launched food should be ≥ The level of the monkey

As the monkey is dropping from the tree the destination of the launched food should be at the monkey so that before the food gets to the position where the monkey was when launching the food with the arrow, the monkey will be slightly lower so as to be able to catch the food or return up the tree to get the food rather than the food falling to the ground.

Answer:

2000 cm³

Explanation:

Assuming the pressure is constant:

V / T = V / T

1000 cm³ / 300 K = V / 600 K

V = 2000 cm³

Answer:

h = 10000 m

Explanation:

The pressure applied at a depth of the liquid is given by:

P =ρgh

where,

P = Maximum Pressure to Survive = (1000)(Atmospheric Pressure)

P = (1000)(101325 Pa) = 1.01 x 10⁸ Pa

ρ = Density of sea water = 1025 kg/m³

g = 9.8 m/s²

h = maximum depth to survive = ?

Therefore,

1.01 x 10⁸ Pa = (1025 kg/m³)(9.8 m/s²)h

h = (1.01 x 10⁸ Pa)/(1025 kg/m³)(9.8 m/s²)

h = 10000 m

Explanation:

Boyles law is the pressure of a fixed mass of gas which is inversely proportional to its volume provided that the temperature is kept constant.

Answer:

a) -1.25 m/s²

b) 62.5 m

Explanation:

Convert km/h to m/s:

45 km/h × (1000 m/km) × (1 h / 3600 s) = 12.5 m/s

a = Δv / Δt

a = (0 m/s − 12.5 m/s) / 10 s

a = -1.25 m/s²

Δx = ½ (v + v₀) t

Δx = ½ (0 m/s + 12.5 m/s) (10 s)

Δx = 62.5 m

Answer:

900 cm/s or 9 m/s.

Explanation:

Data obtained from the question include the following:

Length (L) = 30 cm

frequency (f) = 60 Hz

Velocity (v) =.?

Next, we shall determine the wavelength (λ).

This is illustrated below:

Since the wave have 4 node, the wavelength of the wave will be:

λ = 2L/4

Length (L) = 30 cm

wavelength (λ) =.?

λ = 2L/4

λ = 2×30/4

λ = 60/4

λ = 15 cm

Therefore, the wavelength (λ) is 15 cm

Now, we can obtain the speed of the wave as follow:

wavelength (λ) = 15 cm

frequency (f) = 60 Hz

Velocity (v) =.?

v = λf

v = 15 × 60

v = 900 cm/s

Thus, converting 900 cm/s to m/s

We have:

100 cm/s = 1 m/s

900 cm/s = 900/100 = 9 m/s

Therefore, the speed of the wave is 900 cm/s or 9 m/s.

Answer:

Explanation:

Load ( L ) = 500 N

Effort ( E ) = 200 N

Load distance ( LD ) = 3 m

Effort distance ( ED ) = ?

Now, Let's find the Effort distance ( ED )

We know that,

Output work = Input work

i.e L × LD = E × ED

plug the values

[tex]500 \times 3 = 200 \times ED[/tex]

multiply the numbers

[tex]1500 = 200 \times ED[/tex]

Swipe the sides of the equation

[tex]200 \: ED \: = 500[/tex]

Divide both sides of the equation by 200

[tex] \frac{200 \: ED}{200} = \frac{500}{200} [/tex]

Calculate

[tex]ED\: = 2.5 \: m[/tex]

Hope this helps..

best regards!!

I think any pendulum would swing slower on the moon than it would on Earth.

The time it takes a pendulum to go through a complete back and forth swing is:

Time period = 2 π √(length/gravity)

You can see that 'gravity' is in the denominator of the fraction, so the smaller gravity gets, the longer the period gets.

To be a little bit more technical, the period is inversely proportional to the square root of gravity.

So the period for a complete swing on the moon would be  √(9.8/1.6) times as long as the complete swing of the same pendulum on Earth.

That number is roughly 2.47 .

So, for every 1 second that a pendulum takes to swing back and forth once on Earth, the same pendulum would take 2.47 seconds to do it on the moon.

Answer:

based on my opinion....

as we know that gravity in moon are less than gravity in earth.. since the force of gravity is less on the moon, the pendulum would swing slower at the same length, angle

and the frequency would be less.

I hope this helps

Explanation:

In case the resistors are in series

R =R1 + R2

R = 40 ohm + 40 ohm

R = 80 ohm

In case the resistors are in parallel

R = 1/R1 + 1/R2

R = 1/40 + 1/40

R = 2/40 ohm

R = 1/20 ohm or R = 0.05 ohm

dont forget to mark brainliest

Answer:

dtwtwerEtbWt

Explanation:

bwtrbtWbTW4TBW4tbW4T4t

Answer:

16 m

Explanation:

Given:

v₀ = 4 m/s

a = 4 m/s²

t = 2 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (4 m/s) (2 s) + ½ (4 m/s²) (2 s)²

Δx = 16 m

Answer:

Explanation:

The range of mercury thermometer is - 37°C to 356°C . At temperature below - 37°C , mercury starts converting into solid so this thermometer becomes non-  functional . Hence to measure temperature of - 50°C , alcohol thermometer is suitable . The range of alcohol thermometer is - 112° C to 78°C .  

(b) Always act on the different bodies in opposite directions

Answer:

b) Always act on the different bodies in opposite directions

Explanation:

b) Always act on the different bodies in opposite directions

For example:

If I am sitting on a sofa and I exert 370N and the sofa will exert -370N force. If the sofa doesn't exert force back, I won't be able to sit which means it will break.

Hope it helps ;) ❤❤❤

Explanation:

Because of air pressure

Answer:

175 m

Explanation:

Given:

y = 220 m

v₀ = 30 m/s

v = 0 m/s

a = -10 m/s²

Find: y₀

v² = v₀² + 2a (y − y₀)

(0 m/s)² = (30 m/s)² + 2 (-10 m/s²) (220 m − y₀)

y₀ = 175 m

Answer:

Explanation:

A ) Let the angle be θ between magnetic field and velocity of charged particle

Force created on charged particle F

= Bqv sinθ, B is magnetic field , q is charge , v is velocity of charged particle

F = .05 x 2 x 10⁻⁶ x 10⁸ x sinθ

8 = 10 sinθ

sinθ = .8

θ =  53°.

B )

acceleration = force / mass

= 8 / 10⁻²⁰

= 8 x 10²⁰ m / s²

Answer: 0.0180701 s

Explanation:

Given the following :

Length of string (L) = 10 m

Weight of string (W) = 0.32 N

Weight attached to lower end = 1kN = 1×10^3

Using the relation:

Time (t) = √ (weight of string * Length) / weight attached to lower end * acceleration due to gravity

g = acceleration due to gravity = 9.8m/s^2

Weight of string = 0.32N

Time(t) = √ (0.32 * 10) / [(1*10^3) * (9.8)]

Time = √3.2 / 9800

= √0.0003265

= 0.0180701s

Answer:

(d) Water has a high specific heat.

Explanation:

At night, when the temperature of earth goes down due to loss of heat , the temperature of water is lost slowly and temperature of land is lost fast because of high specific heat of water . Water loses as well as gains temperature comparatively slowly due to its high specific heat .

During daytime when earth gains heat , the temperature of land rises more rapidly than water so water appears cool even during daytime when land becomes  hotter . It is also due to high heat holding capacity of water or due to high specific heat of water .

Answer:

*if a hydrogen emission line is observed in the galaxy, this implies that the galaxy has a significant amount of a chemical element

*difference between the two wavelengths e can be explained by the relativistic Doppler effect

Explanation:

The emission of the materials depends on the distribution of the electrons around the atoms and their possible transitions. These emissions are maintained even when the element is mixed in some compound.

Consequently, if a hydrogen emission line is observed in the galaxy, this implies that the galaxy has a significant amount of a chemical element.

The small difference between the two wavelengths e can be explained by the relativistic Doppler effect, due to the movement of the galaxy

Explanation:

F=m(v-u)/t

F=2N

m=2kg

t=2s

2=2(v-u)/2

cross multiply

2*2=2(v-u)

4=2(v-u)

4/2=v-u

v-u=2m/s

v-u is the change is velocity.

The change in velocity of the body in 2 sec is 2m/s

According to Newton's second law which states that the change in momentum of an object is directly proportional to the applied force.

Mathematically:

[tex]F \ \alpha \ (\dfrac{v-u}{t} )[/tex]

[tex]F = m (\dfrac{v-u}{t} )[/tex]

where:

m is the mass

(v - u) is the change in velocity

t is the time

F is the applied force

Given the following:

mass m = 2kg

time t = 2secs

Force F = 2N

Required

Change in velocity (v-u)

Substitute the given parameters into the expression shown above:

[tex]2=2(\dfrac{v-u}{2})\\ 2 \times 2=2(v-u)\\4=2(v-u)\\v-u=\dfrac{4}{2}\\v-u=2m/s\\[/tex]

Hence the change in velocity of the body in 2 sec is 2m/s.

Learn more here: https://brainly.com/question/3232705

Answer:

3.6ft

Explanation:

Using= 2*π*sqrt(L/32)

To solve for L, first move 2*n over:

T/(2*π) = sqrt(L/32)

Next,eliminate the square root by squaring both sides

(T/(2*π))2 = L/32

or

T2/(4π2) = L/32

Lastly, multiply both sides by 32 to yield:

32T2/(4π2) = L

and simplify:

8T²/π²= L

Hence, L(T) = 8T²/π²

But T = 2.1

Pi= 3.14

8(2.1)²/3.14²

35.28/9.85

= 3.6feet

Answer:

it is used because

They are also less likely to jam due to rust in the screw thread.

Hydraulic jacks are often used to lift elevators in low and medium rise buildings.

A hydraulic jack uses a liquid that is forced into a cylinder by a pump plunger.

Answer:

likely to decrease downstream in arid regions and increase downstream in temperate regions

Explanation:

Arid regions are is a region with a severe lack of water, usually to the extent that affect the organisms living in the region. Arid regions are characterized by a very low depth of rainfall per year. Temperate region on the other hand experience more distinct seasonal change and wider temperature change. Temperate regions get a fairly large amount of rainfall per year.

In arid regions, the soil is very dry, and the rate of infiltration and percolation is high relative to the amount of rainfall available. The effect is that more water is infiltrated into the soil as you move downstream, leading to a decrease in the discharge of a stream as you move downstream. Most temperate region have soils that are usually saturated in the peak of the rainfall season, leading to a greater stream discharge as you move downstream.  

Answer: 17cm.

Explanation:

The equation you're using is:

Δd = df - di

Which means the change in position is equal to the final position minus the starting position. In this case that works out to 20cm - 3cm = 17cm. We're only interested in how much the snail moved, not how long it took to move, so even though they give a time it actually doesn't matter for this question.

Answer:

0.66c

Explanation:

Use length contraction equation:

L = L₀ √(1 − (v²/c²))

where L is the contracted length,

L₀ is the length at 0 velocity,

v is the velocity,

and c is the speed of light.

900 = 1200 √(1 − (v²/c²))

3/4 = √(1 − (v²/c²))

9/16 = 1 − (v²/c²)

v²/c² = 7/16

v = ¼√7 c

v ≈ 0.66 c

Answer:

No

Explanation:

lambda represent wavelength

Lambda is a letter in the Greek alphabet. You need it to spell many words in Greek. Also, if you like, you can use it as a variable in an algebraic expression, or as a name for your cat, or to represent a physical or chemical quantity.

The quantity you use it to represent may or may not have dimensions or units of measurement.