Answer:
[tex]t = 0.55[/tex]
Explanation:
Given
[tex]Height, s = 1.5m[/tex]
[tex]Velocity, v = 70m/s[/tex]
Required
Determine the time to hit the ground
Using free fall formula:
[tex]S = \frac{1}{2}gt^2[/tex]
Take g as 9.8 and substitute value for S
[tex]1.5 = \frac{1}{2} * 9.8 * t^2[/tex]
[tex]1.5 = 4.9 * t^2[/tex]
Make t^2 the subject
[tex]t^2 = \frac{1.5}{4.9}[/tex]
[tex]t^2 = 0.30612244898[/tex]
Solve for t
[tex]t = \sqrt{0.30612244898[/tex]
[tex]t = 0.55[/tex] -- approximated
An astronaut on the Moon releases a rock from rest and allows it to drop straight downward. If the acceleration due to gravity on the Moon is 1.62m/s2 and the rock falls for 2.4s before hitting the ground, what is its speed just before it lands?
Answer:
speed before landing = 3.9 m/s (3 s.f.)
Explanation:
As rock is released from rest, u = 0 m/s a = 1.62 m/s² t = 2.4 s v = ?
v = u + at
v = 0 + (1.62 x 2.4)
v = 3.888 = 3.9 s (3 s.f.)
Hope this helps!
The speed of the rock before hitting the ground is 3.89 m/s
The given parameters;
acceleration due to gravity on moon, g = 1.62 m/s²
time taken for the object to fall, t = 2.4 s
To find:
the speed of the object before hitting the ground;The maximum height of fall of the rock is calculated as;
[tex]h = v_0t + \frac{1}{2} gt^2\\\\v_0 = 0\\\\h = \frac{1}{2} gt^2\\\\h = 0.5 \times 1.62 \times 2.4^2 \\\\h = 4.67 \ m[/tex]
The speed of the rock before hitting the ground is calculated as;
[tex]v_f^2 = v_0 ^2 + 2gh\\\\v_f^2 = 0 + 2\times 1.62 \times 4.67\\\\v_f^2 = 15.13\\\\v_f = \sqrt{15.13} \\\\v_f = 3.89 \ m/s[/tex]
Thus, the speed of the rock before hitting the ground is 3.89 m/s
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A rock is at the top og a 20 meter tall hill. The rock has a mass of 10 kg. How much potential energy does it have
Answer:
1962 joules
Explanation:
m = 10 kg
h = 20 m
g = 9.81 ms^-2
PE = ?
PE = MGH
PE = 10 x 9.81 x 20
PE = 1962 joules
A light wave passes through an aperture (that is, a narrow slit). When it does so, the degree to which the wave spreads out will be...
Explanation:
Single slit diffraction
Diffraction is the phenomenon of spreading out of waves as they pass through an aperture or around objects. Diffraction occurs when the size of the aperture or obstacle is of the same order of magnitude as the wavelength of the incident wave. For very small aperture sizes, the vast majority of the wave is blocked. in case of large apertures the wave passes by or through the obstacle without any significant diffraction.
A 3 kg mass is travelling in a circle of 0.1 m radius with a speed of 2 m/s. What is the centripetal acceleration?
a = v² / R = (2 m/s)² / (0.1 m) = 40 m/s²
A student adds two vectors of magnitudes 48 m and 22 m. What are the maximum and minimum possible values for the resultant of these two vectors.
Answer:
Maximum=70 m
Minimum=26 m
Explanation:
Vector Addition
Since vectors have magnitude and direction, adding them takes into consideration not only the magnitudes but also their respective directions. Two vectors can be totally collaborative, i.e., point to the same direction, or be totally opposite. In the first case, the magnitude of the sum is at maximum. Otherwise, it's at a minimum.
Thus, the maximum magnitude of the sum is 48+22 = 70 m and the minimum magnitude of the sum is 48-22= 26 m
0.0884 moles of a diatomic gas
are in a piston. When the piston
is compressed, the temperature
drops by 18.8 K, and 83.7 J of
heat flow out. Find W.
(Be careful with + and - signs.
+W = expansion, +Q = added,
+AU = temp goes up)
(Unit = J)
Answer:
W = - 118.24 J (negative sign shows that work is done on piston)
Explanation:
First, we find the change in internal energy of the diatomic gas by using the following formula:
[tex]\Delta\ U = nC_{v}\Delta\ T[/tex]
where,
ΔU = Change in internal energy of gas = ?
n = no. of moles of gas = 0.0884 mole
Cv = Molar Specific Heat at constant volume = 5R/2 (for diatomic gases)
Cv = 5(8.314 J/mol.K)/2 = 20.785 J/mol.K
ΔT = Rise in Temperature = 18.8 K
Therefore,
[tex]\Delta\ U = (0.0884\ moles)(20.785\ J/mol.K)(18.8\ K)\\\Delta\ U = 34.54\ J[/tex]
Now, we can apply First Law of Thermodynamics as follows:
[tex]\Delta\ Q = \Delta\ U + W[/tex]
where,
ΔQ = Heat flow = - 83.7 J (negative sign due to outflow)
W = Work done = ?
Therefore,
[tex]-83.7\ J = 34.54\ J + W\\W = -83.7\ J - 34.54\ J\\[/tex]
W = - 118.24 J (negative sign shows that work is done on piston)
Answer:
-49.2
Explanation:
Trust me bro
Starting with the definitions of momentum and kinetic energy, derive an equation for the kinetic energy of a particle expressed as a function of its momentum.
Answer:
[tex]K.E = (\frac{1}{2})Pv[/tex]
Explanation:
The momentum of a particle is defined as the product of its mass and velocity:
[tex]P = mv[/tex] -------------------- equation (1)
where,
P = momentum of the particle
m = mass of the particle
v = velocity of the particle
The kinetic energy of the particle is given as follows:
[tex]K.E = (\frac{1}{2})mv^2\\\\K.E = (\frac{1}{2})v(mv)[/tex]
using equation (1), we get:
[tex]K.E = (\frac{1}{2})Pv[/tex]
HELP right awayyy !!!
Answer:
Question 4 is actually Acceleration
Alex, parked by the side of an east-west road, is watching car P, which is moving in a westerly direction. Barbara, driving east at a speed 52 km/h, watches the same car. Take the easterly direction as positive. If Alex measures a speed of 78 km/h for car P, what velocity will Barbara measure?
Answer:
[tex]v_{PB} = 130\ km/h[/tex]
Explanation:
Since, Alex is at rest. Therefore, the speed measured by him will be the absolute speed of car P. Therefore, taking easterly direction as positive:
[tex]Absolute\ Velocity\ of\ Car\ P = v_{P} = -78\ km/h[/tex]
And the absolute velocity of Barbara's Car is given as:[tex]Absolute\ Velocity\ of\ Barbara's\ Car = v_{B} = 52\ km/h[/tex]
Now, for the velocity of Car p with respect to the velocity of Barbara's Car can be given s follows:
[tex]Velocity\ of\ Car\ P\ measured\ by\ Barbara = v_{PB} = v_{B}-v_{P}\\\\v_{PB} = 52\ km/h-(-78\ km/h)[/tex]
[tex]v_{PB} = 130\ km/h[/tex]
What is the period of an object that makes 6 revolutions a minute?
Answer:
T = 10 s
Explanation:
First, we need to find the frequency of the object as follows:
[tex]Frequency = f = \frac{Speed\ in\ rpm}{60}[/tex]
where,
Speed = Angular Speed = 6 rpm
Therefore,
[tex]f = \frac{6\ rpm}{60}\\\\f = 0.1\ Hz[/tex]
Now, for time period (T):
[tex]Time\ Period = T = \frac{1}{f}\\\\T = \frac{1}{0.1\ Hz}\\\\[/tex]
T = 10 s
Is electricity matter?
EXPLAIN.
Answer:
Yes it is matter
Explanation:
In physics, usually the word "electricity" isn't really used. "Electric current" is more common, and is defined as the flow of charges, where the charges are held by particles (electrons). Electrons have mass, so they are definitely matter.
Energy stored because of an object's height above the Earth's surface is_____energy.
nuclear
gravitational
electrical or chemical
An image is a copy of an objecí formed by what light
Answer:
Plane mirror
Explanation:
A virtual image is a copy of an object formed at the location from which the light rays appear to come.
An object 2.7 cmtall is placed12 cmin front of a mirror. •What type of mirror and what radius of curvature are needed to createan upright image that is 5.4 cm in height? •What is the magnification of the image?
Answer:
a. Concave mirror, radius of curvature = 16 cm b. magnification = 2
Explanation:
a. Since the image is upright and larger than the object, we need a concave mirror.
We know image height, h'/object height, h = -image distance, d'/object distance, d
h'/h = -d'/d
Using the real is positive convention,
h'= + 5.4 cm, h = + 2.7 cm and d = + 12 cm.
So, + 5.4 cm/+ 2.7 cm = -d'/+ 12 cm
2 = -d'/12
d' = -2 × 12 cm
= -24 cm
Using the mirror formula 1/d + 1/d' = 2/r where r = radius of curvature of the mirror
1/+12 + 1/- 24 = 2/r
1/12(1 - 1/2) = 2/r
1/12(1/2) = 2/r
1/24 = 2/r
r/2 = 24
r = 2 × 24
r = 48 cm
b.
magnification = image height, h'/object height,h = + 5.4 cm/+ 2.7 cm = 2
en the current in one coil changes at a rate of 3.2 A/s, an emf of 5.7 is induced in a second, nearby coil. What is the magnitude of the mutual inductance of the two coils
Given that,
The rate of change of current = 3.2 A/s
Emf induced in the coil = 5.7 V
To find,
The magnitude of the mutual inductance of the two coils.
Solution,
The mutual inductance between the coils is given by the formula as follows :
[tex]\epsilon=M\dfrac{dI}{dt}\\\\M=\dfrac{\epsilon}{\dfrac{dI}{dt}}\\\\M=\dfrac{5.7}{3.2}\\\\=1.78\ H[/tex]
So, the mutual inductance of the two coils is 1.78 H.
Thomas the Tank Engine (a train) is going 80 m/s and slows down to 30 m/s over a period of 30s. What is his deceleration? Acceleration= (final velocity-initial velocity)/ time A. -1.67 m/s/s B. 0.67 m/s/s C. -50 m/s/s D. 50 m/s/s
Answer: D
Explanation:
Which wave has high enough energy to cause damage to skin and sometimes cancer?
Answer: All UV can have harmful effects on biological matter (such as causing cancers) with the highest energies causing the most damage.
Explanation:
At 3.00 m from a source that is emitting sound uniformly in all directions, the sound level (b) is 60.0 dB.
How many meters from the source would the sound level be one-fourth the sound level at 3.00 m?
Given that,
At 3.00 m from a source that is emitting sound uniformly in all directions, the sound level is 60.0 dB.
To find,
The distance from the source would the sound level be one-fourth the sound level at 3.00 m.
Solution,
The intensity from a source is inversely proportional to the distance.
Let I₁ = 60 dB, r₁ = 3 m, I₂ = 60/4 = 15 dB, r₂ =?
Using relation :
[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\\r_2^2=\dfrac{I_1r_1^2}{I_2}\\\\r_2^2=\dfrac{60\times (3)^2}{15}\\\\r_2=6\ m[/tex]
So, at a distance of 6 m the sound level will be one fourth of the sound level at 3 m.
if a certain car, going with speed v1, rounds a level curve with a radius r1, it is just on the verge of skidding. if its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:
Answer:
The correct answer is 4R1
Explanation:
According to the given scenario ,the radius of the tightest curve on the same road without skidding is as follows:
As we know that
Centeripetal Acceleration is
= v^2 ÷ r
In the case when velocity becomes 2 times so the r would be 4 times
So, the radius of the tightest curve on the same road without skidding is 4R1
What causes the magnetic field around the wire?
Magnetic field
O A. An electric current
O B. An electric field
PREVIOUS
An electric current causes the magnetic field around the wire. The correct answer is A.
The magnetic field around a wire is caused by the flow of electric current through the wire. When an electric current passes through a wire, it generates a magnetic field that forms circular lines of magnetic flux around the wire. This phenomenon is described by Ampere's law, which states that a magnetic field is produced by an electric current and its strength is directly proportional to the magnitude of the current.
The relationship between the electric current and the magnetic field can be understood using the right-hand rule. If you wrap your right hand around the wire with your thumb pointing in the direction of the current, the curled fingers indicate the direction of the magnetic field lines.
Therefore, an electric field is generated by an electric charge, not by an electric current. While an electric field can exist around a wire if there is a potential difference (voltage) applied across it, it is the flow of electric current that primarily generates the magnetic field.
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A water-skier of mass 75.0 kg initially at rest is being pulled due east by a horizontal towrope. The rope exerts a force of 365 N (east). The water (and air) exerts a combined average frictional force of 190 N (in the opposite direction). How fast will the skier be moving after a distance of 38.0 m?
Answer:
The skier will be moving at 13.31 m/s.
Explanation:
To calculate the velocity of the skier we need to find the acceleration, as follows:
[tex] \Sigma F = ma [/tex]
[tex] F_{r} - F_{f} = ma [/tex]
Where:
[tex] F_{r}[/tex]: is the force due to the rope = 365 N
[tex] F_{f}[/tex]: is the combined average frictional force = 190 N
m: is the mass = 75.0 kg
[tex] a = \frac{365 N - 190 N}{75.0 kg} = 2.33 m/s^{2} [/tex]
Now, we can calculate the velocity of the skier by using the following kinematic equation:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad [/tex]
Where:
[tex] v_{f}[/tex]: is the final velocity =?
[tex] v_{0}[/tex]: is the initial velocity = 0 (the skier is initially at rest)
d: is the distance = 38.0 m
[tex] v_{f} = \sqrt{2*2.33 m/s^{2}*38.0 m} = 13.31 m/s [/tex]
Therefore, the skier will be moving at 13.31 m/s.
I hope it helps you!
Two students (90.0 kg and 60.0 kg) on roller skates face-to-face push against each other. The 90.0 kg student moves at 5.0 m/s just after their hands lose contact. What is the velocity of the other student?
Given that,
Mass of student 1, m₁ = 90 kg
Mass of student 2, m₂ = 60 kg
Speed of student 1, v₁ = 5 m/s
To find,
The velocity of the other student.
Solution,
Using the conservation of momentum to find the velocity of the other student. Let it is v₂.
[tex]m_1v_1=m_2v_2\\\\v_2=\dfrac{m_1v_1}{m_2}\\\\v_2=\dfrac{90\times 5}{60}\\\\=7.5\ m/s[/tex]
So, the velocity of the other student is 7.5 m/s.
. Emily pushes a 38.8 kg grocery cart of groceries by exerting a 76.0 N force on the handle inclined at 40.0 degrees below the horizontal. What are:
a. The horizontal and vertical components of Emily’s force
b. The acceleration of the cart?
Answer:
a) [tex]F_{x} = 58.2 N[/tex]
[tex] F_{y} = 48.9 N [/tex]
b) a = 1.5 m/s²
Explanation:
a) The horizontal and vertical components of Emily's force can be found knowing the angle and the exerted force.
Since the handle is inclined at 40.0° below the horizontal we have:
[tex] F_{x} = |F|*cos(\theta) = 76.0 N*cos(40) = 58.2 N [/tex]
[tex] F_{y} = |F|*sin(\theta) = 76.0 N*sin(40) = 48.9 N [/tex]
b) The acceleration of the car can be calculated as follows:
[tex] F_{x} = ma [/tex]
We used the horizontal component of the force because the cart is moving in that direction.
[tex] a = \frac{F_{x}}{m} = \frac{58.2 N}{38.8 kg} = 1.5 m/s^{2} [/tex]
Hence, the acceleration of the car is 1.5 m/s².
I hope it helps you!
The scientific method can easily be misinterpreted as ___________. Question 1 options: a great magical trick, or slide of hands, rather than factual an "auto mechanics" guide to Science Investigation a "cookbook" recipe for performing scientific investigations the perfect method for finding the answers to all questions
Answer:
I think the answer is
a "cookbook" recipe for performing scientific investigations
Explanation:
A particular engine has a power output of 5 kW and an efficiency of 30%. If the engine expels 6464 J of thermal energy in each cycle, find the heat absorbed in each cycle. Answer in units of J.
Answer:
The heat absorbed in each cycle is 9,234.286 J
Explanation:
Given;
power output, P = 5 kW = 5,000 W
efficiency of the engine, e = 30 % = 0.3
thermal heat expelled, [tex]Q_c[/tex] = 6464 J
let the heat absorbed = [tex]Q_h[/tex]
The efficiency of the engine is given as;
[tex]e = \frac{W}{Q_h} = \frac{Q_h-Q_c}{Q_h} = \frac{Q_h}{Q_h} - \frac{Q_c}{Q_h} = 1-\frac{Q_c}{Q_h}\\\\e = 1-\frac{Q_c}{Q_h}\\\\0.3 = 1-\frac{Q_c}{Q_h}\\\\\frac{Q_c}{Q_h} = 1-0.3\\\\\frac{Q_c}{Q_h} = 0.7\\\\Q_h = \frac{Q_c}{0.7} \\\\Q_h = \frac{6464}{0.7} = 9,234.286 \ J.[/tex]
Therefore, the heat absorbed in each cycle is 9,234.286 J.
Two wave pulses pass each other on a string. The pulse traveling toward the right has positive amplitude, whereas the pulse traveling toward the left has equal amplitude in the negative direction. What happens when they occupy the same region of space at the same time?
a. constructive interference occurs
b. destructive interference occurs.
c. a standing wave is produced.
d. a traveling wave is produced.
e. a wave pulse is produced.
Answer:
destructive interference occurs
Conveyor belts are often used to move packages around warehouses. The conveyor shown below moves packages at a steady 4.0 m/s. A 500 N employee decides to catch a ride by sitting on a 1,000 N box for a 50 m trip as shown below:
What is the work done by the employee on the box?
Answer:
0 j
Explanation:
The work done by the employee on the box at the given zero displacement is 0 J.
The given parameters;
Constant velocity of the conveyor, v = 4 m/sWeight of the employee, W = 500 NWeight of the box, W = 1,000 NDistance of the trip, h = 50 mThe work done by the employee on the box is calculated as follows;
W = Fd
where;
F is the applied force on the box by employee = weight of the employeed is the distance through which the box is movedSince the employee sits on the box without moving it, the distance moved by the box = 0
W = 500 x 0
W = 0 J
Thus, the work done by the employee on the box is 0 J.
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what is the main cause of seafloor spreading?
Answer:
As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense.
Explanation:
Answer: The main cause of sea floor spreading are the directions and force of the moving tectonic plates.
Explanation:
are aliens real in 2020
Answer:
i believe that they are or there's something out there
Explanation:
:)
the question is in a picture
Answer:
same for all objects
Explanation:
earth pulls every object by same force of gravity