Answer:
F = 37.5 N
Explanation:
It is given that,
Mass of the object is 5 kg
Acceleration of the object is 7.5 m/s²
We need to find the force experienced by the object. The force is given by the product of mass and acceleration of an object. So,
F = m
[tex]F=5\times 7.5\\\\F=37.5\ N[/tex]
So, the force acting on the object is 37.5 N.
. Desde el borde de una azotea de un edificio, se lanza un cuerpo hacia abajo con una velocidad de 20 m/s, si el edificio mide 105 m. ¿Cuántos segundos dura la caída?
Answer:
t = 3.01 s
Explanation:
In order to calculate how long it takes to the object to fall to the ground, you use the following formula, for the calculation of the height:
[tex]y=y_o-v_ot-\frac{1}{2}gt^2[/tex] (1)
yo: height of the building = 105 m
vo: initial velocity of the body = 20m/s
g: gravitational acceleration = 9.8m/s^2
t: time = ?
To find the time t, you take into account that when the body arrives to the ground the height is zero, that is, y = 0.
You replace the values of all parameters in the equation (1), and you obtain a quadratic polynomial for t:
[tex]0=105-20t-\frac{1}{2}(9.8)t^2\\\\0=-4.9t^2-20t+105[/tex]
Next, you use the quadratic formula to get the roots of the polynomial:
[tex]t_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
a = -4.9
b = -20
c = 105
[tex]t_{1,2}=\frac{-(-20)\pm\sqrt{(-20)^2-4(-4.9)(105)}}{2(-4.9)}\\\\t_1=3.01s\\\\t_2=-7.09s[/tex]
You choose the positive value t1, because it has physical meanning.
Hence, the body takes 3.01s to arrive to the ground
b) Explain the method of preparing electromagnet. How do you test the
poles of an electromagnet with the help of magnetic compass ?
Answer:
An electromagnet is made by forming a coil around a soft iron bar (known here as the metal) such as a nail or screw and connect with an insulated copper wire (known here as the electric current conductor) the ends of the wound copper is then connected separately to the positive and negative terminals of a battery (known here as the source of electric current)
The north seeking needle of the magnetic compass will move away when brought close to the north pole of the formed electromagnet which can then be labelled N
The magnetic compass needle will be attracted to the south pole of the electromagnet which can then be labelled S
Explanation:
An electromagnet is an electric powered magnet that is formed (temporarily) by the perpendicular movement of electric current with respect to a metal core
The magnitude and the poles of an electromagnet can be changed by changing the magnitude and the direction of flow of the electric current respectively.
Just need the answer to D please
The boat has to pull with MORE force. Don't forget about the force of friction with the water, pulling the skier in the backwards direction. The force that accelerates him is the NET force ... boat force minus water resistance. So the boat force has to be greater than the net accelerating force.
Julie is cycling at a speed of 3.4 meters/second. If the combined mass of the bicycle and Julie is 30 kilograms, what is the kinetic energy?
A.
1.7 × 102 joules
B.
1.5 × 102 joules
C.
2.0 × 102 joules
D.
2.2 × 102 joules
Answer:
A
Explanation:
Just recall the formula for the gain in kinetic energy and substitute the values in.
A closed-pipe resonator has a length of 1.73 m. The frequency of its second harmonic if the speed of sound is 343 m/s is: a)49,5 Hz b)99.13 Hz c)20.6 Hz d)72 Hz
Answer:
There is no answer, since a closed-pipe resonator can NOT have a second harmonic. However, if you were to plug the pipe length and the speed of sound into the closed-pipe equation anyway you would get 49.56 as your fundamental frequency, which means that 99.13 would be your "plug and play" 2nd harmonic.
Explanation:
Help me pretty please
Answer:a
Explanation:
A train takes 2h to reach station B from station A and 3h to return back to A.The distance between the station is 200km, then its average speed would be
Answer:
80km/hr
Explanation:
Total distance: 400km
Total time 5 hours
Average speed= distance/time
400/5= 80km/hr
Un gas se encuentra a una presión constante y a una temperatura de 30°C. Si la temperatura aumenta a 45°C, su presión varía a 6 atm. ¿Cuál era la presión inicial del gas? Transforma los °C en °K.
Answer:
P1 = 5.76 atm
Explanation:
To find the initial pressure of the gas you use the equation for ideal gases, for both temperatures and pressures:
[tex]P_1V=nRT_1\\\\P_2V=nRT_2\\\\[/tex]
T1: initial temperature = 30°C = 303.15K
T2: final temperature = 45°C = 318.15K
P1: initial pressure = ?
P2: final pressure = 6atm
n: number of moles
R: ideal gas constant
The number of moles and R are constant, you can dive the first equation into the second and solve for P1:
[tex]\frac{P_1V}{P_2V}=\frac{nRT_1}{nRT_2}\\\\\frac{P_1}{P_2}=\frac{T_1}{T_2}[/tex]
[tex]P_1=\frac{T_1P_2}{T_2}[/tex]
Finally, you replace the values of T1, P2 and T2:
[tex]P_1=\frac{(303.15K)(6atm)}{318.15K}=5.71atm[/tex]
hence, the initial pressure of the gas was 5.71 atm
Explain the following behaviour of molecules water rises up in a harrow tubes but mercury which is also a liquid falls in a narrow tubes to level below the outside surface
Answer: find the answer in the explanation
Explanation:
The capillarity of water molecules is different from the mercury molecules.
What is capillarity ?
This is the tendency of a liquid substance to rise in a capillary tube.
Molecules water rises up in a harrow tubes because of the force of adhesion between the water molecules and the tube molecules is greater than the force of cohesion between the water molecules. This helps water to wet the tube and rise. While mercury which is also a liquid falls in a narrow tubes to level below the outside surface because the force of cohesion between the mercury molecules is greater than the force of adhesion between the mercury molecules and the tube molecules. Mercury does not wet.
What is the centripetal force of an object undergoing uniform circular motion when its radius is doubled and its speed remains constant?
A.
the same as before
B.
twice as great as before
C.
half as great as before
D.
four times as great as before
Answer:
C
Explanation:
Now the centripetal force is that force that keeps the object on course along the circle;
This is expressed mathematically as ;
F = mv^2/ r
Where F - centripetal force
m- mass of the object
v- velocity of the object
r- raduis
Note from the expression as r increases F decreases so if v and the mass is constant if r doubles F will reduce by half.
Answer:
C. half as great as before
Explanation:
A train takes 6 hours to reach Indore from Delhi. If it moves with the speed of 70 km/h, find the distance between Indore and Delhi.
Answer:
Distance = 420 km
Explanation:
Speed = Distance/ Time
Where speed = 70 km/hr and time = 6 hours
Distance = Speed × Time
D = 70 km/hr × 6 hrs
D = 420 km
Answer:
GIVEN DATA :
TIME TAKEN=t=6h
SPEED OF THE TRAIN=v=70km/h
TO FIND:
DISTANCE COVERED=d=?
SOLUTION:
AS WE KNOW THAT
SPEED=DISTANCE COVERED / TIME TAKEN
SPEED × TIME TAKEN = DISTANCE COVERED
70km/h×6h=distance covered
distance covered=420km
A 1380 kg car starts from rest at the top of a 28.0 m long hill inclined at 11.00 degrees. Ignoring friction, how fast is it going when it reaches the bottom of the hill?
Answer:
10.2 m/s
Explanation:
Using conservation of energy:
PE = KE
mgh = ½ mv²
v = √(2gh)
v = √(2 × 9.8 m/s² × 28.0 m × sin 11.0°)
v = 10.2 m/s
The velocity when car reaches the bottom of the hill is 10.2 m/s.
What is mechanical energy?The mechanical energy is the sum of kinetic energy and the potential energy of an object at any instant of time.
M.E = KE +PE
M.E = ½ mv² + mgh
where g is the acceleration due to gravity, v is the velocity, m is the mass and h is the height of the object.
Given is a 1380 kg car starts from rest at the top of a 28.0 m long hill inclined at 11.00 degrees.
Using conservation of energy principle, we have
PE = KE
mgh = ½ mv²
v = √(2gh)
Substitute the values, we get
v = √(2 × 9.8 m/s² × 28.0 m × sin 11.0°)
v = 10.2 m/s
Thus, the velocity when car reaches the bottom of the hill is 10.2 m/s.
Learn more about mechanical energy.
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You apply a force of 54 N to a car jack in order to change a tire. Each "Crank" of the jack is exerted over a distance of
64 cm. What is the work input on the car jack? (Hint: 1m = 100 cm)
Step # 1
Step #2
Step #3
Explanation:
Work = force × distance
W = (54 N) (0.64 m)
W ≈ 35 J
what is web browser
Answer:
A web browser is a software application for accessing information on the World Wide Web
Answer:
web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. When a user requests a web page from a particular website, the web browser retrieves the necessary content from a web server and then displays the page on the screen.
Explanation:
What is the difference between p-n junction diode and extrinsic semiconductor?
Answer:
The difference between P-N junction diode and extrinsic semiconductor is the allowable direction of flow of current
The extrinsic semiconductor can allow current to flow in both directions while the P-N junction diode permits only a unidirectional flow of current
Explanation:
A semiconductor is a substance that has an intermediate conductivity between that of conductors and non conductors
Examples of semiconductors include germanium and cadmium selenide
A semiconductor to which impurities has been added (an activity known as doping) is an extrinsic semiconductor
Based on the functioning of a semiconductor, doping result in the formation of one of two types of semiconductors including;
1) N-type semiconductor that has an extra electron and the charge carriers are electrons
2) P-type semiconductor that has one less (-e⁻) electron and holes are the charge carriers
An extrinsic semiconductor can conduct allow the flow of electricity in both ways
A P-N junction diode consists of both the P and N-type extrinsic semiconductors arranged such that current can flow in only one direction.
Therefore, the difference is that the extrinsic semiconductor can allow current flow in both directions while the P-N junction diode permits only a unidirectional flow of current.
A negative test charge experiences a force to the right as a result of an electric field. Which is the best conclusion to draw based on this description?
a.The electric field points to the left because the force on a negative charge is opposite to the direction of the field.
b.The electric field points to the right because the force on a negative charge is in the same direction as the field.
c.No conclusion can be drawn because the sign of the charge creating the field is unknown.
d.No conclusion can be drawn because the amount of charge on the test charge is unknown.
OPTION B IS THE ANSWER
Answer:
The real answer is A 2023 answer -_-
Explanation:
12.0 V car battery has a voltage drop of 3.4 V when the starter draws 93 A of current. What is the resistance of the starter? O 88 m2 84 mg O 80 m2
Answer:
[tex]R_s = 0.093 \Omega[/tex]
Explanation:
Voltage of the car battery = 12.0 V
Voltage drop in the battery = 3.4 V
The remainder of the voltage is the starter voltage, that is:
Starter voltage = Initial battery voltage - voltage drop
Starter voltage = 12.0 - 3.4
Starter voltage, [tex]V_{s}[/tex] = 8.6 V
Current drawn by starter, [tex]I_s[/tex] = 93 A
According to Ohm's law: [tex]V_s = I_s R_s[/tex]
Starter Resistance, [tex]R_s[/tex] = [tex]V_s/I_s[/tex]
[tex]R_s = 8.6/93\\R_s = 0.093 \Omega[/tex]
A wire having resistance 20 ohm is bent to make a closed square.What is the resistance across the diagonal of square?
Answer:
5 Ω
Explanation:
When it is bent into a square, each side of the square will get 5 Ω resistance. As considered diagonally ,path of the wire between to diagonal points is the two sides of the square (that is half the length of the wire connected in parallel position). Which gives 10 ohm parallel to 10 ohm wire. So it finally read as 5 Ω wire
A 50 - N x m torque acts on a wheel with a moment of inertia 150 kg x m² . If the wheel starts from rest , how long will it take the wheel to make one revolution ?
Answer:
t = 6.17 s
Explanation:
For a 1 revolution movement, [tex]\triangle \theta = 2\pi[/tex]
Torque, [tex]\tau = 50 Nm[/tex]
Moment of Inertia, [tex]I = 150 kg m^2[/tex]
If the wheel starts from rest, [tex]w_{0} = 0 rad/s[/tex]
The angular displacement of the wheel can be given by the formula:
[tex]\triangle \theta = \omega_0 t + 0.5 \alpha t^2[/tex]................(1)
Where [tex]\alpha[/tex] is the angular acceleration
[tex]\tau = I \alpha\\\alpha = \frac{\tau}{I} \\\alpha = 50/150\\\alpha = 0.33 rad/s^2[/tex]
To get t, put all necessary parameters into equation (1)
[tex]2\pi = 0(t) + 0.5(0.33)t^2\\2\pi =0.5(0.33)t^2\\t^2 = \frac{4 \pi}{0.33} \\t^2 = 38.08\\t = 6.17 s[/tex]
The ________ of a particle for a given ‘Interval of time’ is defined as the ratio of total distance travelled to the total time taken.
uniform speed
average speed
uniform velocity
average velocity
Answer:
The average speed of a particle for a given ‘Interval of time’ is defined as the ratio of total distance travelled to the total time taken.
Explanation:
To find the average speed we take the total
distance traveled divided by the time interval.
The space shuttle is accelerated off its launch pad to a velocity of 525 m/s in 18.0 seconds.
What is its average acceleration?
Answer: 29.17m/s^2
Explanation:
Given the following :
Velocity = 525 m/s
Time = 18 seconds
Acceleration = change in Velocity with time
Using the motion equation:
v = u + at
Where v = final Velocity
u = Initial Velocity and t = time
Plugging our values
525 = 0 + a × 18
525 = 18(a)
a = 525 / 18
a = 29.166666
a = 29.17 m/s^2
Objects A and B have equal amounts volumes and are both traveling at 25 miles per hour. Object A is much denser than Object B. Which object has a greater amount of force and why
Answer:
Object A
Explanation:
Mass of an object= Volume × denstiy
Object having higher density will have greater mass
Next,
According to second law of Newton
Force= mass× acceleration
Force= mass× change is velocity/ time
For an equal amount of time, if change in velocity is equal then object with higher mass will have higher force. Hence, greater density, greater is mass and larger is the force.
When the kinetic energy of particles in a substance decreases, what also decreases?
93
The size of the particles in the substance.
The number of particles in the substance.
The substance's specific heat.
The substance's temperature.
Answer: D
The substance's temperature
Explanation:
According to kinetic theory, increase in temperature causes increase in kinetic energy of particles in a system.
When the kinetic energy of particles in a substance decreases, it has nothing to do with the size of the particles and the specific heat capacity of the particles or substance. But it a clear indication that the substance temperature has also decreased.
Answer:
D
Explanation:
A car starts from rest and attains a velocity of 30m/s in 5 sec . calculate the total distance travel by that car and acceleration
Answer:
Acceleration (a) = 6 m/s²
Total distance travel by car(s) = 75 meter
Explanation:
Given:
Initial velocity (u) = 0
Final velocity (v) = 30 m/s
Time (t) = 5 sec
Find:
Total distance travel by car(s) = ?
Acceleration (a) = ?
Computation:
v = u +at
30 = 0 + a(5)
30 = a(5)
Acceleration (a) = 6 m/s²
Total distance travel by car(s) = ut +1/2(a)(t)²
Total distance travel by car(s) = 1/2(a)(t)²
Total distance travel by car(s) = (0.5)(6)(5)²
Total distance travel by car(s) = 75 meter
Njoki planted trees at intervals of 22m apart on the diagonal of a rectangular plot of land that measures 48m by 20m . How many trees did he plant
Answer:
The number of tree is 2Explanation:
the diagonal of the rectangular plot of land can be found using Pythagoras theorem (the diagonal is the hypotenuse)
Given
length of land x= 48m
width of land y= 20m
digonal z= ?
[tex]z^2= x^2+y^2\\\\z=\sqrt{ x^2+y^2} \\[/tex]
substituting the values of x and y into the equation we can solve for z
[tex]z=\sqrt{ 48^2+20^2} \\\\z=\sqrt{ 2304+400} \\z=\sqrt{ 2704} \\z=52m\\[/tex]
The diagonal is 52m
Hence since the interval = 22m the number if treee is
[tex]\frac{52}{22} = 2.36\\[/tex]
The number of trees must be whole numbers , the number of tree is 2
What’s the When the temperature increases the viscosity of the liquids ??? Hurry someone plz help
Answer:
Decreases
Explanation:
Viscosity is inversely proportional to temperature
i.e. η ∝ [tex]\frac{1}{T}[/tex]
Where η is coefficient of viscosity and T is temperature,
Which means that when temperature increases, viscosity decreases and vice versa.
18. Which does not affect the strength of an electromagnet?
A the current in the solenoid
B the temperature of the coil
OC the number of loops in the coil
D the type of ferromagnetic core
Answer:
The temperature does not affect the strength of a magnetExplanation:
An electromagnet is obtained by winding an insulated wire round a soft iron rod with the wire ends connected to a DC source. such magnets have temporary magnetic properties which disappears with time as the current supply is cut off.
Furthermore the strength off an electromagnet
increases as current increasesincreases as the number of turns increasesthe type of magnetic core is highly essential as an iron core will do batter than a silver core
A ball is being rolled by a normal push of 1000N. it is opposed by friction which has a force of 0.3kN and air resistance which has a force of 23N. Calculate the resultant force.
Answer:
677 N
Explanation:
Let F = normal push force = 1000 N, f = frictional force = 0.3 kN = 300 N and f' = air resistance = 23 N.
Since the frictional force and the air resistance are in the opposite direction the the normal push force, the resultant force R is
R = F - f - f'
= 1000 N - 300 N - 23 N
= 677 N
I NEED ANSWER RN OR ILL BE DED
Answer:
i) O m/s² as velocity is constant
ii) 20m/s
iii)Hint:Calculate the area of the graph,that is;below the line, for the first 15 seconds only
Hope this helps.
If a body of mass 10 kg is pushed with a force of 15N, then the acceleration of the body is
Answer:
1.5m/s2
Explanation:
F=ma
a=F/m
a=15/10
a=1.5m/s2
