a simple machine makes our work easier and faster. why?​

Answer:

vₓ = 53.6 km/h

vy = 12.4 km/h

Explanation:

       [tex]v_{x} = v_{o} * cos \theta = 55 km/h * cos 13 = 53.6 km/h[/tex]

       [tex]v_{y} = v_{o} * sin\theta = 55 km/h * sin 13 = 12.4 km/h[/tex]

Explanation:

Recreational water activities can have substantial benefits to health and well-being. Swimming pools, beaches, lakes, rivers and spas provide environments for rest and relaxation, physical activity, exercise, pleasure and fun. Yet they also present risks to health.

pls make it the brainliest of it has helped you !!!!

Answer:

-9m/s²

Explanation:

Given parameters:

Initial velocity = 45m/s

Final velocity  = 0

duration  = 5s

Unknown:

acceleration = ?

Solution:

Acceleration is the rate of change of velocity with time;

        Acceleration  = [tex]\frac{v- u}{t}[/tex]

v is the final velocity

u is the initial velocity

t is the time taken

 Input the parameters and solve;

     Acceleration  = [tex]\frac{0 - 45}{5}[/tex]   = -9m/s²

The car accelerates at a rate of -9m/s² which is a deceleration

Explanation:

Resistors in circuits can either be connected in series or in parallel.

For a series connected resistors, the same current flows through the resistors while different voltages is passed across them. The formula for calculating effective resistances in a circuit is expressed as

[tex]R_T = R_1+R_2+R_3...+R_n[/tex] where R1, R2, R3 etc. are the resistances connected in series.

The effective resistances for series connected resistors is the sum of the individual resistors

For a parallel connected resistors, different current flows through the resistors while same voltage is passed across them. The formula for calculating effective resistances in a circuit is expressed as:

[tex]\frac{1}{R_T} = \frac{1}{R_1} +\frac{1}{R_2} +\frac{1}{R_3} +...\frac{1}{R_n}[/tex]

The effective resistances for parallel connected resistors is the sum of the reciprocal of the individual resistors

Answer:

1.5m/s^2

Explanation:

Answer:

1.5 m/s2. accerelation =force ÷mass

Statements 1,2,3 and 4 match statements B, C, A, and D respectively.A wind turbine converts rotational energy into electrical energy.

According to the Law of conservation of energy. Energy can not be created nor be destroyed, it can transfer from one to another form.

1.A wind turbine converts rotational energy into electrical energy.

2.A roller coaster going downhill converts gravitational energy into mechanical energy

3. Toaster converts electrical energy into thermal energy

4.A car converts rotational energy into mechanical energy.

Hence,statements 1,2,3 and 4 match statements B, C, A, and D respectively.

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Answer: 549.9 km

Explanation: 84.6km every hour so 84.6*6.5= 549.9

Answer:

Options B & E are correct

Explanation:

Looking at all the options, B & E are the correct ones.

Option B is correct because the thicker the wire per unit length, the lesser resistance it will posses and the lesser the energy that will be dissipated by the wire and in return more energy will be dissipated by the bulb.

Option E is also correct because the resistance of the copper wires is low enough to ensure that there's not much drop in voltage across the copper wires. Thus, there will not be any noticeable differences in the voltage across the bulb.

Option A is not correct because the current is not used up and thus the charge is conserved, and it will circulate just through the circuit.

Option C is not correct because although the Electric field along the wire is not zero, it is very small.

Option D is not correct because the wires and the light bulb are connected in series and as such, the current in both the wires and the light bulb will be identical.

The brightness of a bulb that not change noticeably when you use longer copper wires to connect it to the battery is :

b. Very little energy is dissipated in the thick connecting wires.

e. The electric field in connecting wires is very small, so emf almost = E_ bulb * L_bulb.

The brightness of a bulb that not change noticeably when you use longer copper wires to connect it to the battery is very little energy is dissipated in the thick connecting wires and the electric field in connecting wires is very small, so emf almost = E_ bulb * L_bulb.

The thicker the wire per unit length, the lesser resistance it'll posses and the lesser the vitality that will be scattered by the wire and in return more vitality will be disseminated by the bulb.

The resistance of the copper wires is low sufficient to guarantee that there's not much drop in voltage over the copper wires. Hence, there will not be any noticeable contrasts within the voltage over the bulb.

Thus, the correct answer is B and E.

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Answer:

VB

Explanation:

Answer:

The correct solution will be "271.95 N".

Explanation:

The given values are:

velocity  

v = 3.5 m/s

mass

m = 9.0 kg

r = 0.6 m

According to the question:

⇒ [tex]F_{branch}=F_{gravity}+F_{centrifugal}[/tex]

⇒             [tex]=mg+\frac{mv^2}{r}[/tex]

On substituting the values, we get

⇒             [tex]=9\times 9.8+\frac{9\times (3.5)^2}{0.6}[/tex]

⇒             [tex]=88.2+\frac{110.35}{0.6}[/tex]

⇒             [tex]=271.95 \ N[/tex]

Answer:

v₃ = 0.786 m/s

Explanation:

Here, we will use the law of conservation of momentum, which states the following:

Total Momentum of System Before Collision =

Total Momentum of System After Collision

m₁u₁ + m₂u₂ + m₃u₃ = m₁v₁ + m₂v₂ + m₃v₃

where,

m₁ = mass of bullet = 6.13 g = 0.00613 kg

m₂ = mass of 1st block = 1233 g = 1.233 kg

m₃ = mass of 2nd block = 1646 g = 1.646 kg

u₁ = speed of first bullet before collision = 361 m/s

u₂ = speed of first block before collision = 0 m/s

u₃ = speed of 2nd block before collision = 0 m/s

v₁ = speed of bullet after collision

v₂ = speed of 1st block after collision = 0.741 m/s

v₃ = speed of 2nd block after collision = ?

Therefore,

(0.00613 kg)(361 m/s) + (1.233 kg)(0 m/s) + (1.646 kg)(0 m/s) = (0.00613 kg)(v₁) + (1.233 kg)(0.741 m/s) + (1.646 kg)(v₃)

2.2129 kg m/s + 0 kg m/s + 0 kg m/s - 0.9136 kg m/s = (0.00613 kg)(v₁) + (1.233 kg)(0.741 m/s) + (1.646 kg)(v₃)

1.2992 kg m/s = (0.00613 kg)(v₁) + (1.646 kg)(v₃)

since, the bullet is embedded in 2nd block after collision. Thus, there velocities will become same. (v₁ = v₃)

Therefore,

1.2992 kg m/s = (0.00613 kg)(v₃) + (1.646 kg)(v₃)

v₃ = (1.2992 kg m/s)/(1.6521 kg)

v₃ = 0.786 m/s

Answer:

Probability = 0.0244

Explanation:

Probability that Junior Non Physics Major & then a Freshman Non Physics Major are chosen:

Prob (Jr No-Ph Mjr)  = Jr No-Ph Mjr / Total

= 18 / 82 = 0.2195

Prob (Fr No-Ph Mjr) = Fr No-Ph Mjr / Total (remaining)

= 9 / 81 = 0.1111

Prob [ Jr No-Ph Mjr & Fr  No-Ph Mjr ] = 0.2195 x 0.1111 = 0.02439

≈  0.0244

Answer:

hello your question is incomplete attached below is the complete question

21) The current at points B and C would be the same ( identical bulbs) while the current at Point A will be greater than the currents at point B and C. i.e. twice the current at either point B or point C

22) The potential difference across the bulbs will be the same and this is because the bulbs are connected in parallel to the the power source ( battery)

hence the voltage in the battery will be equal to the voltage across each bulb

Explanation:

The current at points B and C would be the same ( identical bulbs) while the current at Point A will be greater than the currents at point B and C. i.e. twice the current at either point B or point C

The potential difference across the bulbs will be the same and this is because the bulbs are connected in parallel to the the power source ( battery)

hence the voltage in the battery will be equal to the voltage across each bulb

Answer:

2.The centripetal force required to keep the pennies in place increases with the distance from the center. Eventually, as the turntable spins faster, the friction force between the turntable and the penny near the edge is not enough to supply the required centripetal force.

Explanation:

centripetal force = m ω² R

here m is mass , ω is angular velocity and R is distance of penny from centre

So this force depends upon R

penny on the outer edge will require  greater centripetal force to move in circular path .

The centripetal force will be provided by frictional force of table which is same for both the coin . Hence the penny on the outer edge will slip off first the moment , frictional force reach its maximum value for it . But it will be sufficient to keep in balance the penny nearer to the centre .

Answer:

7 Newton's East

Explanation:

when the force is going in the same direction in this case east, you add the forces.

Answer:

Philosophy is a study that involves the nature of knowledge and truth. It serves as a guide that helps an individual seek which things are valuable and essential in life. ... It gives you a sense of direction, knowing the weight of things, therefore making you more productive.

Answer:

5.6449

9 mpa

Explanation:

we are to determine mass of steam that has entered and also the pressure of steam.

After solving

Mass of steam = m2 - m1

= 15.925-10.2901

= 5.6449kg

Then the enthalpy of steam was calculated to be 3109.26

Using steam table, tl = 400⁰c

Hl = 3109.26

Supply line pressure = 9mpa

Please refer to attachment for all calculations

Answer:

147.27N

Explanation:

Power = workdone/time

Power = Force*distance/time

Given

Power = 90Watts

Distance = 1.1m

Time = 1.8secs

Force = ?

Substitute the given parameters into the formula:

[tex]90 = \frac{1.1d}{1.8}\\cross \ multiply\\ 90 \times 1.8 = 1.1F\\162 = 1.1F\\1.1F = 162\\F = \frac{162}{1.1} \\F = 147.27N[/tex]

Hence the magnitude of the force that you exert on the handle is 147.27N

Answer:

also choose D and E i belive those are also correct

Answer:

W = 0.012 J

Explanation:

For this exercise let's use Hooke's law to find the spring constant

         F = K Δx

         K = F / Δx

         K = 3 / (0.16 - 0.11)

         K = 60 N / m

Work is defined by

         W = F. x = F x cos θ

in this case the force and the displacement go in the same direction therefore the angle is zero and the cosine is equal to 1

         W = ∫ F dx        

         W = k ∫ x dx

we integrate

         W = k x² / 2

          W = ½ k x²

let's calculate

         W = ½ 60 (0.19 -0.17)²

         W = 0.012 J

Answer:

This answer was wrong

Explanation:

I took the test and I missed this question.  So it is not answer B: pass a literacy test.  

It will need an A. pass a vision and hearing test

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(a) Differentiate the position vector to get the velocity vector:

r(t) = (3.00 m/s) t i - (4.00 m/s²) t² j + (2.00 m) k

v(t) = dr/dt = (3.00 m/s) i - (8.00 m/s²) t j

(b) The velocity at t = 2.00 s is

v (2.00 s) = (3.00 m/s) i - (16.0 m/s) j

(c) Compute the electron's position at t = 2.00 s:

r (2.00 s) = (6.00 m) i - (16.0 m) j + (2.00 m) k

The electron's distance from the origin at t = 2.00 is the magnitude of this vector:

||r (2.00 s)|| = √((6.00 m)² + (-16.0 m)² + (2.00 m)²) = 2 √74 m ≈ 17.2 m

(d) In the x-y plane, the velocity vector at t = 2.00 s makes an angle θ with the positive x-axis such that

tan(θ) = (-16.0 m/s) / (3.00 m/s)   ==>   θ ≈ -79.4º

or an angle of about 360º + θ ≈ 281º in the counter-clockwise direction.

Answer:

1.680kN/m

Explanation:

Work done by the spring is expressed as shown:

[tex]W = \frac{1}{2}ke^2[/tex] where:

k is the spring constant

e is the extension

Given

W = 525Joules

extension = 25cm = 0.25m

Substitute into the formula:

[tex]525 = \frac{1}{2}k(0.25)^{2} \\525 = \frac{0.0625k}{2}\\ 525 = 0.03125k\\k = \frac{525}{0.3125}\\k = 1680N/m\\k = 1.680kN/m[/tex]

Hence the force constant of the spring is 1.680kN/m

Answer:

1. 0.574 kJ/kg

2. 315.7 MW

Explanation:

1. The mechanical energy per unit mass of the river is given by:

[tex] E_{m} = E_{k} + E_{p} [/tex]

[tex] E_{m} = \frac{1}{2}v^{2} + gh [/tex]

Where:

Ek is the kinetic energy

Ep is the potential energy

v is the speed of the river = 3 m/s

g is the gravity = 9.81 m/s²

h is the height = 58 m

[tex] E_{m} = \frac{1}{2}(3 m/s)^{2} + 9.81 m/s^{2}*58 m = 0.574 kJ/Kg [/tex]

Hence, the total mechanical energy of the river is 0.574 kJ/kg.

2. The power generation potential on the river is:

[tex] P = m(t)E_{m} = \rho*V(t)*E_{m} = 1000 kg/m^{3}*550 m^{3}/s*0.574 kJ/kg = 315.7 MW [/tex]

Therefore, the power generation potential of the entire river is 315.7 MW.

I hope it helps you!

Answer:

The average velocity and average speed of the dog are 2.262 meters per second and 6.787 meters per second, respectively.

Explanation:

From Physics we must remember the definitions of average speed and average velocity, both measured in meters per second. Velocity is a vectorial quantity, that is, it has both magnitude and direction, whereas speed is an scalar quantity, which is a quantity that is represented solely by its magnitude. We assume that dog moves at constant speed.

For the case of the dog, we get that average speed and average velocity of the animal are, respectively:

Average velocity:

[tex]\vec v_{avg} = \frac{1}{\Delta t}\cdot (\vec r_{B}-\vec r_{A})[/tex] (Eq. 1)

Where:

[tex]\Delta t[/tex] - Travelling time of the dog, measured in seconds.

[tex]\vec r_{A}[/tex] - Initial vector position of the dog, measured in meters.

[tex]\vec r_{B}[/tex] - Final vector position of the dog, measured in meters.

Average speed:

[tex]v_{avg} = \frac{1}{\Delta t} \cdot (s_{A}+s_{B})[/tex] (Eq. 2)

Where [tex]s_{A}[/tex] and [tex]s_{B}[/tex] are the travelled distances of each stage, measured in meters.

If we know that [tex]\Delta t = 11.05\,s[/tex], [tex]\vec r_{A} = 0\,\hat{i}\,\,\,[m][/tex] and [tex]\vec r_{B} = 25\,\hat{i}\,\,\,[m][/tex], [tex]s_{A} = 50\,m[/tex] and [tex]s_{B} = 25\,m[/tex], average velocity and average speed are, respectively:

[tex]\vec v_{avg} = \frac{1}{11.05\,s}\cdot (25\,\hat{i})\,\,\,[m][/tex]

[tex]\vec v_{avg} = 2.262\,\hat{i}\,\,\,\left[\frac{m}{s} \right][/tex]

[tex]v_{avg} = \frac{75\,m}{11.05\,s}[/tex]

[tex]v_{avg} = 6.787\,\frac{m}{s}[/tex]

The average velocity and average speed of the dog are 2.262 meters per second and 6.787 meters per second, respectively.

Answer:

Explanation:

If a particle move with time and expressed according to the formula:

f(t) = 0.01t⁴ − 0.03t³

a) Velocity is the change in motion of the particle with respect to time and it is expressed as;

[tex]v(t) =\frac{d(f(t))}{dt}[/tex]

[tex]v(t) = 4(0.01)t^{4-1} - 3(0.03)t^{3-1}\\v(t) = 0.04t^3 - 0.09t^2[/tex]

Hence the velocity of the particle at time t is [tex]v(t) = 0.04t^3 - 0.09t^2[/tex]

b) To calculate the velocity after 1 second, we will substitute t = 1 into the function v(t) in (a) as shown:

[tex]v(t) = 0.04t^3 - 0.09t^2\\v(1) = 0.04(1)^3 - 0.09(1)^2\\v(t) = 0.04 - 0.09\\v(t) = -0.05[/tex]

Hence the velocity after 1second is -0.05

c) The particle is at rest when when the time is zero.

Initially, the body is not moving and the time during this time is 0. Hence the particle is at rest when t = 0second

Answer:

Its rotation will be 3.89x10⁴ rad/s.

Explanation:

We can find the rotation speed by conservation of the angular momentum:

[tex] L_{i} = L_{f} [/tex]

[tex] I_{i}\omega_{i} = I_{f}\omega_{f} [/tex]   (1)

The initial angular speed is:

[tex] \omega_{i} = \frac{1 rev}{7 d} = 0.14 \frac{rev}{d} [/tex]

The moment of inertia (I) of a sphere is:

[tex] I = \frac{2}{5}mr^{2} [/tex]    (2)

Where m is 9 times the sun's mass and r is the sun's radius

By entering equation (2) into (1) we have:

[tex] \frac{2}{5}m_{i}r_{i}^{2}\omega_{i} = \frac{2}{5}m_{f}r_{f}^{2}\omega_{f} [/tex]

[tex]9m_{sun}(696342 km)^{2}0.14\frac{rev}{d} = \frac{3}{4}9m_{sun}(13 km)^{2}\omega_{f}[/tex]

[tex]\omega_{f} = \frac{4}{3}*0.14 \frac{rev}{d}(\frac{696342 km}{13 km})^{2} = 5.36 \cdot 10^{8} \frac{rev}{d}*\frac{1 d}{24 h}*\frac{1 h}{3600 s}*\frac{2\pi rad}{1 rev} = 3.89 \cdot 10^{4} rad/s[/tex]          

Hence, its rotation will be 3.89x10⁴ rad/s.

I hope it helps you!                                                        

Answer:

We must apply a force to keep the object moving at a constant velocity due to gravitational force or weight (in case of lifting), and due to frictional force (in case of pushing).

Explanation:

LIFTING:

When an object is lifted, we first need to overcome the force exerted on it by the field of gravity. Due to this force, which is also called the weight of object, we must apply a force on the object to keep it moving at constant speed, otherwise the gravity force will cause the object to slow down and eventually fall back on ground.

PUSHING:

When pushing an object the person must apply the force to first overcome the frictional force. The frictional force acts in opposite direction of motion. Thus, to move the object at constant speed we must apply force to it.

Hence, we must apply a force to keep the object moving at a constant velocity due to gravitational force or weight (in case of lifting), and due to frictional force (in case of pushing).

Answer:

578.66 N

Explanation:

The first step is to calculate the mass

mgh= 3200J

3200/9.8×5.53

3200/54.194

m = 59.047 kg

Therefore the weight can be calculated as follows

Weight = m × g

= 59.047 × 9.8

= 578.66 N