In contact forces, _____.

A.) objects do not touch each other
B.) objects must touch each other
C.) more work is done than in other forces

Answer:

b. identical to the downward force of gravity on the person.

Explanation:

For an object in an elevator,

F = mg - ma       (g > a)

But since the velocity is uniform, a = 0.

Then,

F = mg - 0

F = mg

This is the actual weight of the object.

The object does not feel weightless, so that its actual weight can be measured during the downward motion of the elevator with uniform velocity.

Thus, the upward normal force, N, exerted by the elevator floor on the person is identical to the downward force of gravity on the person.

Answer:

476.35 km

Explanation:

The following data were obtained from the question:

Initial velocity (u) = 11000 km/hr

Final velocity (v) = 0 km/hr (at maximum height)

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

Maximum height (h) = ?

Next, we shall convert 9.8 m/s² to km/hr². This is illustrated below:

1 m/s² = 12960 km/hr²

Therefore,

9.8 m/s² = 9.8 m/s² × 12960 km/hr² / 1 m/s²

9.8 m/s² = 127008 km/hr²

Thus, 9.8 m/s² is equivalent to 127008 km/h²

Finally, we shall determine the maximum height reached by the projectile.

This is illustrated below:

Initial velocity (u) = 11000 km/hr

Final velocity (v) = 0 km/hr (at maximum height)

Acceleration due to gravity (g) = 127008 km/hr²

Maximum height (h) = ?

v² = u² – 2gh (since the projectile is going against gravity)

0² = 11000² – (2 × 127008 × h)

0 = 121×10⁶ – 254016h

Collect like terms

0 – 121×10⁶ = – 254016h

– 121×10⁶ = – 254016h

Divide both side by – 254016

h = – 121×10⁶ / – 254016

h = 476.35 km

Thus, the maximum height reached by the projectile is 476.35 km

Answer:

10m/s²

Explanation:

Given parameters:

Initial velocity  = 0m/s

Final velocity  = 100m/s

Time taken  = 10s

Unknown:

Acceleration  = ?

Solution:

Acceleration is the rate of change of velocity with time.

  A = [tex]\frac{v - u}{t}[/tex]

v = final velocity

u = initial velocity

t = time taken

 So, insert the parameters and solve;

  A = [tex]\frac{100 - 0}{10}[/tex]   = 10m/s²

Answer:Final volume after pressure is applied=4,292cm3

Explanation:

Using the bulk modulus formulae

We have that The bulk modulus of waTer is given as  

K =-V dP/dV

Where  K, the bulk modulus of water = 2.15 x 10^9N/m^2

2.15 x 10^9N/m^2= - 4,300 x  4 × 106N/m2 / dV

dV = - 4,300 x  4 × 10^6N/m^2/ 2.15 x 10^9N/m^2

dV (change in volume)= -8.000cm^3

Final volume after pressure is applied,

V= V+ dV

V= 4300cm3 + (-8.000cm3)

=4300cm3 - 8.000cm3

Final Volume, V =4,292cm3

Answer:

220v

Explanation:

Sorry, the question is incomplete

Answer:

on the potential difference applied and on the resistance of the wire.

Explanation:

Ohms law state that the current through a conductor between two points is directly proportional to the potential difference across the two points. Imtroducing the comstant of proportionality, the resistance, one arrives at the usual athematical equation that describes this relationship: I = V/R.

Answer:

Fluorine is the most reactive

Explanation:

Among the halogens, fluorine, chlorine, bromine, and iodine, fluorine is the most reactive one. It forms compounds with all other elements except the noble gases helium (He), neon (Ne) and argon (Ar), whereas stable compounds with krypton (Kr) and xenon (Xe) are formed.

Answer:

m₂ = 1.17 kg

Explanation:

Given that,

Force between two objects, [tex]F=1.01\times 10^{-8}\ N[/tex]

Mass of object 1, [tex]m_1=5.11\ kg[/tex]

Distance between masses, r = 19.9 cm = 0.199 m

The gravitational force between two masses is given by :

[tex]F=\dfrac{Gm_1m_2}{r^2}[/tex]

m₂ is the mass of object 2

[tex]m_2=\dfrac{Fr^2}{Gm_1}\\\\m_2=\dfrac{1.01\times 10^{-8}\times (0.199)^2}{6.67\times 10^{-11}\times 5.11}\\\\=1.17\ kg[/tex]

So, the mass of second object is 1.17 kg.

Answer:

310 m

Explanation:

120+150+40=310

Answer:

Answer is (b) Mercury, venus and Mars.

Explanation:

i think b is correct!!

;-) :-) :-) :-)

Answer:

10J

Explanation:

In this question we have the following information

The charge of the particle is q = 5 C

The equipotenetial level is V1 = 5.5 v

and also the

equipotenetial level is V2 = 3.5 v

So we calculate the

work done W=q x (v1-v2)

workdone = 5 x (5.5-3.5)

= 5x2

=10 J

Workdone = 10 J

So we conclude that the workdone on a particle with these information is 10j

Explanation:

the formula of speed is distance traveled by time it work

31.25 cm/sec

__________________________________________________________

We are given:

Distance travelled = 150 cm

Time taken = 4.8 seconds

Final Speed of the Marble:

Speed of the marble = Distance travelled / Time taken

Speed of the marble = 150 / 4.8

Speed of the marble = 31.25 cm/sec

Answer:

answer is C on edge 2021

Explanation:

Answer:

10 m/s²

Explanation:

The above question simply indicates motion under gravity.

The acceleration due to gravity (i.e acceleration of free fall) has a constant value of 10 m/s².

Whether the rock is dropped from a height of 5 m or 2.5 m, it will accelerate at 10 m/s² before striking the ground. The only thing that will be different is the time taken for the rock to strike the ground when released from both 5 m and 2.5 m.

Thus, the rock will have a constant acceleration of 10 m/s² irrespective of the height to which it was released.

Since acceleration due to gravity is a constant,  the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s²

Acceleration due to gravity is the acceleration a body falling freely from a height above the earth surface which a body experiences due to the gravitational force of attraction of the earth on the body.

Acceleration due to gravity has a constant value which is equal to 10 m/s².

Therefore, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s².

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Answer:

Explanation:

Time of flight is the time of takes to hit the ground

Given

Height H = 50m

Acceleration due to gravity g = 9.8m/s³

Using the equation of motion;

S = ut+1/2gt²

u = 0m/s

Substitute and get time t

50 = 0(t)+1/2(9.8)t²

50 = 4.9t²

t² = 50/4.9

t² = 10.204

t = √10.204

t = 3.19secs

Hence the time of flight is 3.19secs

Answer:

B, which is why ice skaters often keep their arms close to their body when doing spins and jumps to minimize resistance.

Answer:

36.87°

Explanation:

Given

Maximum height = 60m

Horizontal distance (range) = 80,m

Required

Initial speed U

Angle of launch

To get the speed, we will use the range formula;

R = U √2H/g

80 = U√2(60)/9.8

80 = U√12.25

80 = 3.5U

U = 80/3.5

U = 22.86m/s

Get the angle of launch

Using the formula

Theta = tan^-1(y/x)

y is the vertical distance

x is the horizontal distance

Theta = tan^-1(60/80)

Theta = tan^-1(0.75)

Theta = 36.87°

Hence the angle of launch is 36.87°

Answer:

distance i think

Explanation:

Answer:

60.185 percent of the original kinetic energy is convertible to internal energy.

Explanation:

Let suppose that collision between both particles is entirely inellastic. If there is no external forces exerted on any of the particles, then we can apply the Principle of Linear Momentum Conservation. That is:

[tex]m_{A}\cdot v_{A,o} + m_{B}\cdot v_{B,o} = (m_{A}+m_{B})\cdot v[/tex]

[tex]v = \frac{m_{A}\cdot v_{A,o}+v_{B}\cdot v_{B,o}}{m_{A}+m_{B}}[/tex] (1)

Where:

[tex]m_{A}[/tex] - Mass of the 4.8-g particle, measured in kilograms.

[tex]m_{B}[/tex] - Mass of the 7.4-g particle, measured in kilograms.

[tex]v_{A,o}[/tex] - Initial speed of the 4.8-g particle, measured in meters per second.

[tex]v_{B,o}[/tex] - Initial speed of the 7.4-g particle, measured in meters per second.

[tex]v[/tex] - Final speed of the collided particles, measured in meters per second.

If we know that [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex] and [tex]v_{B,o} = 0\,\frac{m}{s}[/tex], then the final speed of the system is:

[tex]v = \frac{(4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)+(7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)}{4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg}[/tex]

[tex]v = 1.180\,\frac{m}{s}[/tex]

During the collision part of the initial energy is dissipated in the form of heat, which is related to the internal energy ([tex]\Delta U[/tex]), measured in joules. According to the Principle of Energy Conservation, we have the following model:

[tex]\Delta U = K_{A}+K_{B}-K[/tex] (2)

Where:

[tex]K_{A}[/tex], [tex]K_{B}[/tex] - Initial translational kinetic energies of each particle, measured in joules.

[tex]K[/tex] - Final translational kinetic energy of the collided particles, measured in joules.

By applying the definition of translational kinetic energy, we expand and simplify the equation above:

[tex]\Delta U = \frac{1}{2}\cdot m_{A}\cdot v_{A,o}^{2}+\frac{1}{2}\cdot m_{B}\cdot v_{B,o}^{2} -\frac{1}{2}\cdot (m_{A}+m_{B})\cdot v^{2}[/tex] (3)

If we get that  [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex], [tex]v_{B,o} = 0\,\frac{m}{s}[/tex] and [tex]v = 1.180\,\frac{m}{s}[/tex], the internal energy associated with the system is:

[tex]\Delta U = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)^{2}+ \frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}-\frac{1}{2}\cdot (4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg)\cdot \left(1.180\,\frac{m}{s} \right)^{2}[/tex]

[tex]\Delta U = 0.013\,J[/tex]

And the initial energy of both particles is:

[tex]E_{o} = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s}\right)^{2}+\frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}[/tex]

[tex]E_{o} = 0.0216\,J[/tex]

Lastly, the percentage of the original kinetic energy that is convertible to internal energy is: ([tex]\Delta U = 0.013\,J[/tex], [tex]E_{o} = 0.0216\,J[/tex])

[tex]\%e = \frac{\Delta U}{E_{o}}\times 100\,\%[/tex] (4)

[tex]\%e = \frac{0.013\,J}{0.0216\,J}\times 100\,\%[/tex]

[tex]\%e = 60.185\,\%[/tex]

60.185 percent of the original kinetic energy is convertible to internal energy.

Answer:

Explanation:

Step one:

given data

we are told that 1 large pizza can be cut into 8 even slices

Required

we want to find how many slices are there in 4 large pizzas

Step two:

so if 1 pizza has 8 slices

       4 pizza will have x

cross multiply we have

x= 8*4

x=32 slices

Answer:

Image result for total velocity definition

The average speed of an object is defined as the distance traveled divided by the time elapsed.

Explanation:

Answer:

in the water cycle evaporation occurs when the sunlight warms the surface of the water the heat from the sun makes the water molecules move faster and faster until they move so fast they can escape as a gas once evaporated a molecule from water that vapor spends about 10 days in the air

Answer:

2.9 cm

Explanation:

Assuming that the rear wheel has a radius of 0.330 m

Given that

r(a) = 12 cm -> 0.12 m

w(a) = 0.6 rev/s -> 3.77 rad/s

v = 5 m/s

r(w) = 0.330 m

The speed on any point on the rim at the sprocket in the front is

v(a) = w(a).r(a) = 3.77 * 0.12 = 0.4524 m/s

Also,

v(a) = speed at any point on the chain

v(b) = speed at any point on the rim of the rear sprocket

v(a) = v(b)

where v(b) = w(b).r(b)

Recall that the speed at any point on the rear wheel is v, where

v = w(b).r(w)

5 = w(b) * 0.330

w(b) = 5/0.330

w(b) = 15.15 rad/s

On substituting this in the equation, we have

v(b) = w(b).r(b).

Remember also, that v(a) = v(b), so

0.4524 = 15.15 * r(b)

r(b) = 0.4524 / 15.15

r(b) = 0.029 m -> 2.9 cm

Therefore, the radius of the rear sprocket needed is 2.9 cm

Answer:

D. will decrease slightly in volume when heated to 6° C

Explanation:

A gram of distilled water at 4° C  will increase slightly in volume when heated to 6 C. Hence option C is correct.

Water has the chemical formula H2O, making it an inorganic substance. It is the primary chemical component of the Earth's hydrosphere and the fluids of all known living things (in which it serves as a solvent[1]). It is translucent, flavourless, odourless, and almost colourless. In spite of not supplying food, energy, or organic micronutrients, it is essential for all known forms of life. Its molecules are made up of two hydrogen atoms joined by covalent bonds and have the chemical formula H2O. The angle at which the hydrogen atoms are joined to the oxygen atom is 104.45°.[2] The liquid condition of H2O at normal pressure and temperature is known as "water" as well.

Water occurs because the environment on Earth is pretty near to the triple point of water.

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Answer:

e

Explanation:

cause you have any attachments are not sure if you can get it

When a block slides down an inclined plane, normal force does zero work. Hence, option (a) is correct.

The definition of force in physics is: The push or pull on a massed object changes its velocity.

An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. A spring balance can be used to calculate the Force. The Newton is the SI unit of force.

The component of a contact force in mechanics known as the normal force is perpendicular to the surface that an item encounters.

As normal force always acts perpendicular to the motion, this force does zero work.

But friction force the weight acts in opposite direction of the motion, this force does work against the motion.

In an inclined plane, the parallel component of  weight does work along the motion.

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Answer:

This question is incomplete

Explanation:

This question is incomplete. However, to determine the bicyclist that traveled the fastest at the end of the race, the speed of the bicyclists at the end of the race will determine this (not the bicyclist that came first nor there overall speed). The speed of the bicyclist at the end of the race can be determined by using the formula below

s = d ÷ t

Where s is the speed of each bicyclist at the end of the race

d is the specific distance covered by the bicyclist at the end of the race

t is the time taken for the bicyclist to complete that distance

It should be noted that to get an accurate result, the distance covered at the end of the race must be the same for all the bicyclists.

Answer:

v = 0.823 m/s

Explanation:

A man walks south at a speed of 2.00 m/s for 60.0 minutes.

The distance covered in South = 60 × 60 × 2 = 7200 m

He then turns around and walks north a distance 3000 m in 25.0 minutes.

As they moved in opposite direction, net displacement will be : 7200 - 3000 = 4200 m

Average velocity of the man = net displacement/time

[tex]v=\dfrac{4200\ m}{(60+25)\times 60}\\\\=0.823\ m/s[/tex]

So, the average velocity of the man is 0.823 m/s.

Answer:

A vibration is a repeated back-and-forth or up-and-down motion.

Explanation:

Waves carry energy through empty space or through a medium without transporting matter.

Answer:

The distance moved is 82 m.

The displacement is 18 m to the south.

Explanation:

The distance is a measure of the total length traveled along the path, while the displacement only takes into account the length between the starting position (departure) and final position (arrival). That is, distance refers to how much space an object travels during its movement, being the amount moved, while displacement refers to the distance and direction of the final position with respect to the initial position of an object.

So, the distance being the sum of the distances traveled, you get:

18 m + 22 m + 14 m + 28 m= 82 m

The distance moved is 82 m.

You know that the tennis ball moves 18 meters to the north, then 22 meters to the south, then 14 meters to the north, and finally 28 meters to the south. Then the tennis ball moves:

Calculating the displacement as the difference between the final position and the initial position, you get:

displacement= 50 m - 32 m= 18 m

The displacement is 18 m to the south.