find its instantaneous velocity at point a . express your answer in meters per second to two significant figures.

Answer:

36.75 N

Explanation:

Applying

F = mgμ................. Equation 1

Where F = Friction force on the box, m = mass of the box, g = acceleration due to gravity of the box, μ = coefficient of static friction

From the question,

Given: m = 15 kg, μ = 0.25

Constant: g = 9.8 m/s²

Substitute these values into equation 1

F = 15(9.8)(0.25)

F = 36.75 N

Hence the friction force on the box is 36.75 N

The work done on the crate to move it vertically is 7000 J.

The work done to move a 1400-N crate at constant speed 5.0 m vertically is 7000 J. Here's the explanation:When an object is lifted up at a constant speed, the force applied to it is equal and opposite to the force of gravity acting on it. As a result, no net force is applied to the object, and no work is performed against it.The formula to determine the work done isW = FdwhereW is work doneF is forceand d is distance coveredTo calculate the work done on the crate to move it vertically upwards, we need to determine the force that needs to be applied to overcome gravity acting downwards. We know that force is equal to mass multiplied by acceleration, which means that the force required to overcome gravity acting on the crate is given by:F = mgwhereF is the force in Newtonsm is the mass in kilogram is the due to acceleration, 9.8 m/s²Substitute the given values into the formula:F = 1400 NNext, we need to determine the distance over which the crate is lifted vertically, which is given as d = 5.0 m.Substitute the given values into the formula: d = 5.0 mFinally, substitute the values into the formula to get the work done.W = FdW = 1400 N × 5.0 mW = 7000 J.

for more such questions on crate

https://brainly.com/question/15262937

#SPJ8

The amount of work required to move the crate is determined as 7,000 J.

The amount of work required to move the crate is calculated from the product of applied force and the displacement of the crate.

Mathematically, the formula for work done is given as;

W = Fd

where;

The amount of work required to move the crate is calculated as;

F = 1400 N x 5.0 m

F = 7,000 J

Thus, the amount of work required to move the crate is calculated from the product of applied force and the displacement of the crate.

Learn  more about work done here: https://brainly.com/question/8119756

#SPJ1

The owner's velocity is in the opposite direction of the combined velocity of the dog and the cat, and its magnitude is approximately 0.916 m/s.

To solve the given problem, we can use the principle of conservation of momentum to find the direction and magnitude of the owner's velocity.

Let's denote the velocity of the dog as v1 (northward), the velocity of the cat as v2 (eastward), and the velocity of the owner as v (unknown).

According to the conservation of momentum, the total momentum before the interaction is equal to the total momentum after the interaction.

The total momentum before the interaction is given by:

Total momentum before = (mass of the dog * velocity of the dog) + (mass of the cat * velocity of the cat) + (mass of the owner * velocity of the owner)

Mass of the dog (m1) = 24.4 kg

Velocity of the dog (v1) = 2.14 m/s

Mass of the cat (m2) = 5.53 kg

Velocity of the cat (v2) = 3.56 m/s

Mass of the owner (m3) = 78.5 kg

Velocity of the owner (v) = unknown

Total momentum before = (24.4 kg * 2.14 m/s) + (5.53 kg * 3.56 m/s) + (78.5 kg * v)

The total momentum after the interaction is zero since the owner has the same momentum as the pets taken together.

Total momentum after = 0

Equating the two expressions:

(24.4 kg * 2.14 m/s) + (5.53 kg * 3.56 m/s) + (78.5 kg * v) = 0

Simplifying the equation:

(52.216 kg·m/s) + (19.6488 kg·m/s) + (78.5 kg * v) = 0

71.8648 kg·m/s + (78.5 kg * v) = 0

Solving for v:

78.5 kg * v = -71.8648 kg·m/s

v = -71.8648 kg·m/s / 78.5 kg

v ≈ -0.916 m/s

Therefore, the direction of the owner's velocity is opposite to the combined velocity of the dog and the cat, and the magnitude of the owner's velocity is approximately 0.916 m/s.

For more such information on: velocity.

https://brainly.com/question/80295

#SPJ8

Answer:

The central nervous system is generally made of brain and spinal cord.

Explanation:

Answer:

» Force is 200,000 Newtons

Explanation:

\({ \tt{force = \frac{impulse}{time} }} \\ \\ { \tt{force = \frac{20000}{0.1} }} \\ \\ { \tt{force = 200000 \: newtons}}\)

The magnitude of the force P provided that the stress in the part AB is two times that of BC part is 0.8 kN.

The magnitude of the force P provided that the stress in the part AB is two times that of BC part is calculated as follows;

Take moment about the joint to determine the magnitude of the force along part BC.

120 kN x 750 mm  =  F x 1000 mm

F = ( 120 kN x 750 mm ) / ( 1000 mm )

F = 90 kN

Stress is given as force divided by area. The following equation can be used to determine the magnitude of force P.

Stress in AB = 2 times stress in BC

P/A₁  = 2F/A₂

where;

A₁ =  πd²/4  =  π(50 x 10⁻³)²/4

A₁ = 1.96 x 10⁻⁵ m²

A₂ = πd²/4  =  π(75 x 10⁻³)²/4

A₂ = 4.42 x 10⁻³ m²

P/A₁ = 2F/A₂

P = (2F x A₁) / (A₂)

P = (2 x 90 kN x 1.96 x 10⁻⁵ m² ) / ( 4.42 x 10⁻³ m² )

P = (2 x 90,000 N x 1.96 x 10⁻⁵ m² ) / ( 4.42 x 10⁻³ m² )

P = 798.2 N

P = 0.798 kN

P ≈ 0.8 kN

Learn more about stress-forces here: https://brainly.com/question/929277

#SPJ1

Answer:

1.142

Explanation:

In the physical activity pyramid, sedentary activities belong to Level D.

The Physical Activity Pyramid is a graphic representation of the different types of physical activities that are recommended for a healthy lifestyle.

The pyramid is divided into four levels, with the most important activities at the bottom and the least important at the top. The greatest and most significant activities for healthy everyday life are at the bottom and the least healthy activities at the top, which you should only perform occasionally.

Sedentary activities, which are activities that involve little or no physical movement, belong at the top of the pyramid, in Level D.

Level D is the smallest section of the pyramid, and it represents activities that should be limited in order to maintain good health.

Hence, option D is the correct choice.

For a similar question on the Physical Activity Pyramid,

https://brainly.com/question/18893749

#SPJ4

Answer:

jack has done more work pulling more weight and Jill has more power.

Explanation:

Answer:

C) The book's inertia carried it forward.

When the bus stops suddenly, the book tends to remain in motion due to its inertia. The book was at rest on the seat of the bus, and when the bus stopped suddenly, the book continued moving forward with the same speed and direction it had before the bus stopped. As a result, the book slid off the seat and onto the floor.

To calculate the electric force between two charges, we can use Coulomb's law:

F = k * |q1 * q2| / r^2

where F is the electric force, k is the electrostatic constant (k ≈ 8.99 × 10^9 N m^2/C^2), q1 and q2 are the magnitudes of the charges, and r is the distance between the charges.

In this case, q1 = 0.0042 C, q2 = -0.0050 C, and r = 0.0030 m.

Substituting these values into the equation:

F = (8.99 × 10^9 N m^2/C^2) * |0.0042 C * (-0.0050 C)| / (0.0030 m)^2

F = (8.99 × 10^9 N m^2/C^2) * 0.000021 C^2 / 0.000009 m^2

F ≈ 1977.78 N

Therefore, the electric force between the two charges is approximately 1977.78 Newtons.

Answer:

9800 m

Explanation:

During acceleration, given:

v₀ = 0 m/s

a = 39.2 m/s²

t = 10.0 s

Find: v and Δy

v = at + v₀

v = (39.2 m/s²) (10.0 s) + 0 m/s

v = 392 m/s

Δy = v₀ t + ½ at²

Δy = (0 m/s) (10.0 s) + ½ (39.2 m/s²) (10.0 s)²

Δy = 1960 m

During free fall, given:

v₀ = 392 m/s

v = 0 m/s

a = -9.8 m/s²

Find: Δy

v² = v₀² + 2aΔy

(0 m/s)² = (392 m/s)² + 2 (-9.8 m/s²) Δy

Δy = 7840 m

Therefore, h = 1960 m + 7840 m = 9800 m.

Answer:

bb kettle

Explanation:

it transfres electricsl to kinetic

The work exerted on the car by the engine is 250 Joules.

What is Work?

Work is a physical quantity that is defined as the force applied to an object over a distance. It is a scalar quantity and is measured in units of joules (J) in the International System of Units (SI). The formula for work is W = F x d, where F is the force applied and d is the distance over which the force is applied.

The work exerted on the car by the engine can be calculated using the formula:

Work = Power x Time

Since the car is moving at a constant velocity, we can calculate the time it takes for the engine to exert the given power by using the formula:

Velocity = Work / Time

So, we can find time by using:

Time = Work / Velocity

Substituting the given values, we have:

Time = (750 watts) / (3m/s)

Therefore, the work exerted on the car by the engine is:

Work = Power x Time

Work = 750 watts x (750 watts / 3m/s)

Work = 750 * 250 Joules

So, the work exerted on the car by the engine is 250 Joules.

To learn more about work from the given link:

https://brainly.com/question/25573309

#SPJ1

It has to overcome friction and air resistance in order for your balloon car to start to move

What is a balloon car?

For balloon-powered car, the contracting balloon pushes the air in the balloon backwards. That means the air in the balloon is pushing balloon forwards. The balloon is joined to car, so the car rolls. The motion is nothing to do with pushing on the air behind car.

Learn more about balloon car at https://brainly.com/question/13293570

#SPJ13

The pressure at the upper level of a water flow into the house by means of pipe is 1081 kPa.

Calculate the cross-sectional area of the lower pipe:

A₁ = πr₁²

where:

A₁ = cross-sectional area of the lower pipe (m²)

π = mathematical constant (3.14)

r₁ = radius of the lower pipe (m)

A₁ = π(0.12 m)² = 0.0452 m²

Calculate the cross-sectional area of the upper pipe:

A₂ = πr₂²

where:

A₂ = cross-sectional area of the upper pipe (m²)

π = mathematical constant (3.14)

r₂ = radius of the upper pipe (m)

A₂ = π(0.06 m)² = 0.0113 m²

Calculate the flow rate per unit area:

q = Q/A

where:

q = flow rate per unit area (m³/s)

Q = flow rate (m³/s)

A = cross-sectional area (m²)

q = 6 m³/s / 0.0452 m² = 13.28 m²/s

Calculate the velocity of the water in the lower pipe:

v₁ = q/A₁

where:

v₁ = velocity of the water in the lower pipe (m/s)

q = flow rate per unit area (m³/s)

A₁ = cross-sectional area of the lower pipe (m²)

v₁ = 13.28 m²/s / 0.0452 m² = 29.3 m/s

Calculate the velocity of the water in the upper pipe:

v₂ = q/A₂

where:

v₂ = velocity of the water in the upper pipe (m/s)

q = flow rate per unit area (m³/s)

A₂ = cross-sectional area of the upper pipe (m²)

v₂ = 13.28 m²/s / 0.0113 m² = 117.0 m/s

Calculate the head loss:

hL = (v₁² - v2₂²) / 2g

where:

hL = head loss (m)

v₁ = velocity of the water in the lower pipe (m/s)

v₂ = velocity of the water in the upper pipe (m/s)

g = acceleration due to gravity (9.8 m/s²)

hL = (29.3 m/s)² - (117.0 m/s)² / 2(9.8 m/s²) = 23.2 m

Calculate the pressure at the upper level:

p₂ = p₁ + ρghL

where:

p₂ = pressure at the upper level (Pa)

p₁ = pressure at the lower level (Pa)

ρ = density of water (1000 kg/m³)

g = acceleration due to gravity (9.8 m/s²)

hL = head loss (m)

p₂ = 400 kPa + 1000 kg/m³(9.8 m/s²)(23.2 m) = 1081 kPa

Therefore, the pressure at the upper level is 1081 kPa.

Find out more on pressure here: https://brainly.com/question/28012687

#SPJ1

Recall the definition of average acceleration:

a = (v - u)/∆t

where u and v are the initial and final velocities, respectively.

So we have

2.2 m/s² = (v - 9.3 m/s) / (5.1 s)

v - 9.3 m/s = (2.2 m/s²) * (5.1 s)

v = 9.3 m/s + (2.2 m/s²) * (5.1 s)

v = 20.52 m/s ≈ 21 m/s

Answer:

The below diagram shows pure spectrum with white light

Explanation:

Each of the five friends needs to pay £12 to cover the cost of their own meals and contribute towards the birthday person's meal. Using mean allows us to distribute the cost equally among the friends, ensuring a fair division of expenses for the meal.

To determine how much each of the five friends needs to pay, we can use the concept of averages (mean) and divide the total cost by the number of people paying.

In this scenario, the total cost of the meal for 6 people is £12 per person. Since the other 5 friends have decided to pay for the birthday person's meal, they will collectively cover the cost of their own meals plus the birthday person's meal.

To calculate the total cost covered by the five friends, we can subtract the cost of one person's meal (since the birthday person's meal is being paid by the group) from the total cost. The cost of one person's meal is £12.

Total cost covered by the five friends = Total cost - Cost of one person's meal

= (£12 x 6) - £12

= £72 - £12

= £60

Now, to find out how much each of the five friends needs to pay, we divide the total cost covered by the five friends (£60) by the number of friends (5).

Amount each friend needs to pay = Total cost covered by the five friends / Number of friends

= £60 / 5

= £12

For more such information on: mean

https://brainly.com/question/1136789

#SPJ8

Answer:

m = 0.5

Explanation:

Given that,

The length of the blade of scissors = 5 cm

The length of the handle = 2.5 cm

Here, effort arm is 2.5 cm and load arm is 5 cm. The mechanical advantage is the ratio of effort arm to the load arm as follows :

\(m=\dfrac{2.5}{5}\\\\m=0.5\)

So, the ideal mechanical advantage of a pair of scissors is 0.5.

Answer:    E: 6.0

Explanation:

If the switch is closed, and the circuit is allowed to reach steady state. The resulting steady-state current supplied by the battery is 6 A, hence option E is correct.

When the voltage across the resistor is equal to the battery voltage, we can use Ohm's Law to determine the steady state current. Where I is the current in amps and V is the voltage in volts.

At steady state, the equivalent circuit will look like there is no current flowing across the resistor because the inductor has zero resistance and behaves like a piece of wire that is short-circuited.

Due to the same potential difference across, the battery's steady-state current supply is,

i =  e ÷ R

= 30 ÷ 5

= 6 A

Therefore, the resulting steady-state current supplied by the battery is 6 A.

Learn more about current, here:

https://brainly.com/question/15726481

#SPJ2

Answer:

The angular acceleration of CD player is \(13.93\ rad/s^2\).

Explanation:

Initial angular speed of a CD player is 0 and final angular speed is 41.8 rad/s. Time to change the angular speed is 3 s.

It is required to find the angular acceleration. The change in angular speed of the CD player divided by time taken is called its angular acceleration. It can be given by :

\(a=\dfrac{\omega_f-\omega_i}{t}\\\\a=\dfrac{41.8-0}{3}\\\\a=13.94\ rad/s^2\)

So, the angular acceleration of CD player is \(13.93\ rad/s^2\).

According to the Keynesian view, manipulating foreign sector spending is not a reliable way to move the U.S. economy toward a more acceptable equilibrium because it does not address the fundamental causes of economic instability.

Keynesian economics focuses on the role of domestic demand in driving economic growth and stability. The government can use fiscal and monetary policy to stimulate aggregate demand and promote full employment. However, changes in foreign sector spending can be unpredictable and beyond the control of domestic policymakers. For instance, an increase in foreign demand for U.S. exports could boost economic growth and employment in the short run, but it may not be sustainable if the foreign demand later decreases. Similarly, a decrease in foreign demand for U.S. exports could have negative short-term effects on the economy, but it may not necessarily lead to a long-term decline. In short, Keynesian economics emphasizes the importance of domestic demand management and stabilizing the economy through government intervention. While changes in foreign sector spending can have some impact on the economy, they are generally seen as unreliable and unpredictable, and therefore not a reliable tool for achieving economic stability in the long run.

For such more questions on reliable

https://brainly.com/question/27968241

#SPJ11

In Physics, when we measure a specifig magnitude, we need a reference point to compare with. If you wan't to know your position, you have to related to some reference point, otherwise, you won't be able to do it. All this means that motion (movement) is the change of your position in reation to a fixed point, a reference point.

Therefore, the answer is C.

Firstly, we need to remember how to find the liquid charge for a single atom. We can start by saying that

Where Q is the total charge, np is the number of protons, qp is the charge of a proton, ne is the number of electrons and qe is the charge of an electron

As we know, the charge of an electron is the opposite of the proton's. If we consider it as -1 and 1, respectively, we're left with

Then, let us find the charge for each atom.

So, for our atoms, we have

Then, our answer is

To resolve the star-planet system at a distance of 4 light-years, a telescope on Earth would need an aperture with a minimum diameter of 55.88 mm.

In optical microscopy, the Rayleigh criterion is frequently used to estimate the resolution of the microscope. The resolution limit imposed by this criterion has long been regarded as a roadblock to using an optical microscope to study biological phenomena at the nanoscale.

We can use the Rayleigh criterion,

θ = 1.22 λ / D

θ = angular resolution

λ = wavelength of light

D = diameter of the telescope's aperture

θ = arctan (r / d)

r = radius of the planet's orbit

d = distance to the star

Now, we use the given values,

r = 149.6×106 km = 149.6×109 m

d = 4 × 9.461×1015 m = 3.7844×1016 m

λ = 550 nm = 550×10-9 m

θ = arctan (r / d)

   =arctan (149.6×109 / 3.7844×1016) = 0.000012 radians

we can use the Rayleigh criterion,

θ = 1.22 λ / D

D = 1.22 λ / θ

D = 1.22 × 550×10-9 / 0.000012

D = 55.88 mm

To know more about the Rayleigh criterion visit:

https://brainly.com/question/19953205

#SPJ1

Answer:

Because the matter in solid objects doesn't move

Explanation:

Logic