Answer:
D)378kJ
Explanation:
Applying,
E = F×d................ Equation 1
Where E = Energy expanded by the car, F = Wind resistance, d = distance
From the question,
F = 0.42v²............ Equation 2
Susbtitute equation 2 into equation 1
E = 0.42v²d.............. Equation 3
Given: v = 30 m/s, d = 1 km = 1000 m
Substitute these values into equation 3
E = 0.42(30²)(1000)
E = 378000
E = 378 kJ
Hence the right option is D)378kJ
amount of pressure of liquid increases with ?
Answer: Pressure increases as the depth increases.
Answer:
depths cause it help it with a lot and that it the answer
Adverb of place:
1
Adverb of time:
2
Adverb of place:
3
Adverb of time:
4
Adverb of place:
5
Answer:
1 there,here, somewhere,nowhere,everywhere
2.now,yesterday,then,
A football player collides with another player. The force of the collision is
1000 kg•m/s. The collision lasts 1 second. What is the impulse?
Answer:
Impulse = 1000 Ns
Explanation:
Given the following data;
Force of collision = 1000 kg•m/s.
Time = 1 seconds
To find the impulse;
Mathematically, the impulse experienced by an object or body is given by the formula;
Impulse = force * time
Substituting into the formula, we have;
Impulse = 1000 * 1
Impulse = 1000 Ns
Constants Periodic Table Part A Carla holds a ball 1.5 m above the ground. Daniel, leaning out of a car window, also holds a ball 1.5 mm above the ground. Daniel drives past Carla at 40 mph and, just as he passes her, both release their balls at the same instant.
Whose ball hits the ground first?
The balls will hit the ground simultaneously.
Daniel's.
Carla's The answer can't be determined from the data provided
Answer:
correct answer is c
The balls will hit the ground simultaneously
Explanation:
This is an exercise in kinematics, let's analyze each case separately
Carla. Holds the ball at an initial height y = 1,5m and releases the ball therefore its initial velocity is zero v₀ = 0
y = y₀ + v₀ t - ½ gt²
0 = y₀ + 0 - ½ g t²
t = [tex]\sqrt{\frac{2y_o}{g} }[/tex]
Daniel This holds the ball at I = 1.5 m and releases the ball as it passes by Carla, therefore the initial velocity is
horizontal vox = 40 mph
vertical v_{oy} = 0
y = y_{oy}I + v_{oy} t - ½ g t²
0 = y_{oy} + 0 - ½ g t²
t = [tex]\sqrt{\frac{2 y_o}{g} }[/tex]
we can see that they both spend the same time reaching the ground
t = [tex]\sqrt{2 \ 1.5 / 9.8}[/tex]
t = 0.55 s
The correct answer is c
The balls will hit the ground simultaneously
a net force of 5N is applied to a 13kg mass. what is its acceleration?
Answer:
[tex]\boxed {\boxed {\sf a \approx 0.4 \ m/s^2}}[/tex]
Explanation:
According to Newton's Second Law of Motion, force is the product of mass and acceleration.
[tex]F= m \times a[/tex]
The net force is 5 Newtons and the mass is 13 kilograms. Let's convert the units for force to make the problem and unit cancellation easier.
1 Newton (N) is equal to 1 kilogram meter per square second (1 kg*m/s²) The net force of 5 N is equal to 5 kg*m/s²Now we know the values for 2 variables:
F= 5 kg*m/s²m= 13 kgSubstitute the values into the formula.
[tex]5 \ kg *m/s^2 = 13 \ kg * a[/tex]
Since we are solving for the accleration we must isolate the variable, a. It is being multiplied by 13 kilograms and the inverse of multiplication is division. Divide both sides by 13 kg
[tex]\frac {5 \ kg *m/s^2}{13 \ kg}= \frac{ 13 \ kg *a}{13 \ kg}[/tex]
[tex]\frac {5 \ kg *m/s^2}{13 \ kg}=a[/tex]
The units of kilograms (kg) cancel.
[tex]\frac {5 m/s^2}{13 }=a[/tex]
[tex]0.384615385\ m/s^2=a[/tex]
The original measurements of force and mass ( 5 and 13) have 1 and 2 significant figures. We must round our answer to the least number of sig figs: 1.
For the number we found, that is the tenths place. The 8 in the hundredth place (0.384615385) tells us to round the 3 up to a 4.
[tex]0.4 \ m/s^2 \approx a[/tex]
The acceleration is approximately 0.4 meters per square second.
What is the kinetic energy of a 10kg object moving at 2.0m/s? *
Answer:
20J
Explanation:
[tex]KE = \frac{1}{2} mv^{2} = \frac{1}{2} (10)(2)^{2} =20J[/tex]
What is the rate at which distance changes called
Answer:
a yard
Explanation:
Light with some unknown wavelength is incident on a piece of copper. The most energetic electrons emitted from the copper have 2.7 eV of kinetic energy. If the copper is replaced with a piece of sodium, what will be the maximum possible kinetic energy K of the electrons emitted from this new surface
This question is in complete, the missing table is uploaded along this answer.
Answer:
the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
Explanation:
Given the data in the question;
copper K = 2.7 eV
If the copper is replaced with a piece of sodium ( Na )
the maximum possible kinetic energy K of the electrons emitted from this new surface = ?
we know that;
Kinetic energy of emitted electrons can be written as;
K = hv - hv₀
where v is frequency, h is Plank's constant, and hv₀ is work function of metal
so lets make hv the subject of formula;
hv = K + hv₀
from the table below, work function of copper is 4.5 eV
so we substitute
hv = 2.7 eV + 4.5 eV
hv = 7.2 eV
Now, If the copper is replaced with a piece of sodium ( Na )
we have;
K = hv - hv₀
from the table below, work function of Sodium is 2.3 eV
so we substitute
K = 7.2 eV - 2.3 eV
K = 4.9 eV
Therefore, the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
With the frequency set at the mid-point of the slider and the amplitude set at the mid-point of the slider, approximately how many grid marks is the wavelength of the wave (use the pause button and step button as you need to in order to get a good measure, and round to the nearest whole grid mark)?
If the amplitude is increased the wavelength:___________.
a. decreases
b. stays the same
c. increases
Answer:
correct answer is b
Explanation:
The frequency of a wave depends on the properties of medium density and the elasticity properties change the amplitude depends on the energy carried by the wave, that is, the amplitude is proportional to the height of the wave (oscillation).
Consequently the amplitude of independent of the frequency because it depends on different factors.
Therefore when changing the amplitude the wavelength remains constant
the correct answer is b
We could, in theory, make all of our industrial processes sustainable if we could ________.
a. speed up the disposal of wastes by deep-well injection
b. develop more draconian policies to regulate manufacturing
c. reduce the use of biodegradable plastics
d. transform cyclic processes into linear ones
e. transform linear processes into circular ones
Answer:
transform linear processes into circular ones.
Which nucleus completes the following equation?
Answer:
Option D. ²⁰⁸₈₄Po
Explanation:
From the question given above, the following data were obtained:
²¹²₈₆Rn —> ⁴₂He + ?
Let the unknown be ⁿₓD. Thus, the equation becomes:
²¹²₈₆Rn —> ⁴₂He + ⁿₓD
Next, we shall determine n, x and D. This can be obtained as follow:
212 = 4 + n
Collect like terms
212 – 4 = n
208 = n
n = 208
86 = 2 + x
Collect like terms
86 – 2 = x
84 = x
x = 84
ⁿₓD => ²⁰⁸₈₄D = > ²⁰⁸₈₄Po
²¹²₈₆Rn —> ⁴₂He + ²⁰⁸₈₄Po
Thus, option D gives the correct answer to the question.
An electric eel develops a potential difference of 470 V , driving a current of 0.85 A for a 1.0 ms pulse. Part A Find the power of this pulse.
Answer:
399.5 Watts.
Explanation:
From the question given above, the following data were obtained:
Potential difference (V) = 470 V
Current (I) = 0.85 A
Time (t) = 1 ms
Power (P) =?
Electrical power is defined by the following equation:
Power (P) = potential difference (V) × current (I)
P = IV
Using the above formula, the power can be obtained as follow:
Potential difference (V) = 470 V
Current (I) = 0.85 A
Power (P) =?
P = IV
P = 470 × 0.85
P = 399.5 Watts
Therefore, the power is 399.5 Watts.
Một dây dẫn mảnh được uốn thành một
cung tròn bán kính 10cm, góc ở tâm
bằng 1200
, đặt trong không khí. Trong
dây dẫn có dòng điện cường độ 30A
chạy qua. Độ lớn của cảm ứng từ tại
tâm của cung tròn là bao nhiêu ?
Plz help!! WILL MARK BRAINLIEST :)
Which forces are easier to anticipate and
design for, internal or external? Why do
you think this is so?
Answer:
The external forces such as wind, water and the vibration of the earth when an earthquake happens create internal forces within a structure. Internal forces such as shear, tension and compression can destroy the inner framework of a building or a bridge even though it is made of super strong steel and concrete.
I Hope This Will Help You ...
What is the average speed (in km/h) of Zhana, who runs to the store that is 4.0 km away in 30.0 minutes?
0.13 km/ h
8.0 km/h
2.0 km/h
Answer:
2.0km/h.
Explanation:
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4.Upthrust doesnt depend on the following Physical quantity?
volume of body
density of body
mass of body
acceleration due to gravity
Answer:
C: Mass of body
Explanation:
Upthrust is defined as the upward force that a liquid will exert on a body floating atop it.
Now, Formula for upthrust is;
Upthrust = density of liquid × volume of the body × acceleration due to gravity.
From the formula, we can see that upthrust depends on density, volume and acceleration due to gravity.
Thus, looking at the options, the one that doesn't apply is mass of body.
a typical cmall flashlight contains two batteries each having na emf of 2.0 v connected in series with a bulb havin ga resistance of 16 ohms if the internal resistance of the batteries is negligible what power is delivered to the ublb
Answer:
P = 0.25 W
Explanation:
Given that,
The emf of the battry, E = 2 V
The resistance of a bulb, R = 16 ohms
We need to find the power delivered to the bulb. We know that, the formula for the power delivered is given by :
[tex]P=\dfrac{V^2}{R}\\\\P=\dfrac{2^2}{16}\\\\=0.25\ W[/tex]
So, 0.25 W power is delivered to the bulb.
write the chemical equation of rust
ANSWER
4Fe+ 3O2 → 2Fe2O.
EXPLANATION
iron (Fe) combines with oxygen (O2) to form rust, or iron oxide (Fe2O3). The equation for this reaction is: 4Fe+ 3O2 → 2Fe2O.
During a circus act, an elderly performer thrills the crowd by catching a cannon ball shot at him. The cannon ball has a mass of 72.0 kg and its horizontal component of velocity is 6.50 m/s just before the 65.0 kg performer catches it. If the performer is initially motionless on nearly frictionless roller skates, what is his speed immediately after catching the cannon ball
Answer:
3.416 m/s
Explanation:
Given that:
mass of cannonball [tex]m_A[/tex] = 72.0 kg
mass of performer [tex]m_B[/tex] = 65.0 kg
The horizontal component of the ball initially [tex]\mu_{xA}[/tex] = 6.50 m/s
the final velocity of the combined system v = ????
By applying the linear momentum of conservation:
[tex]m_A \mu_{xA}+m_B \mu_{xB} = (m_A+m_B) v[/tex]
[tex]72.0 \ kg \times 6.50 \ m/s+65.0 \ kg \times 0 = (72.0 \ kg+65.0 \ kg) v[/tex]
[tex]468 kg m/s + 0 = (137 kg)v[/tex]
[tex]v = \dfrac{468\ kg m/s }{137 \ kg}[/tex]
v = 3.416 m/s
FORCE AND DISPLACEMENT AT AN ANGLE A sailor pulls a boat a distance of 30.0 m along a dock using a rope that makes a 25.0° angle with the horizontal. How much work does the rope do on the boat if its tension is 255 N?
Answer: 6117.58 J
Explanation:
We know that W=Fd*cos(theta) where theta is the angle between the displacement and the force.
In this case, we are given that F=225 N, d=30 m, and theta=25 degrees.
Plugging all this in we get
W=225*30*cos(25)=6117.58 J
Work done by the rope when sailor pulls the boat in the dock is 6930.9 J
What is work ?The work is defined by the product of force and displacement. Its standard formula is,
[tex]W = F.d.Cos\alpha[/tex]
Here F is force, d is displacement and α is angle subtended by force from horizontal.
As given in the question,F = 255N, d = 30m, α = 30°
On putting in the above formulaW = 255×30×Cos30°
=7650×0.906
= 6930.9 J
To learn more about work here
https://brainly.com/question/4095205
#SPJ2
Which of the following would NOT produce a current? A. Moving a bar magnet inside a coil of wire O B. Moving a bar magnet toward a straight wire C. Moving a straight wire toward a bar magnet O D. Placing a bar magnet next to a wire.
Answer:
c
Explanation:
Answer:C
Explanation:
A package of mass m is released from rest at a warehouse loading dock and slides down a 3.0-m-high frictionless chute to a waiting truck. Unfortunately, the truck driver went on a break without having removed the previous package, of mass 2m, from the bottom of the chute. Suppose the packages stick together. What is their common speed after the collision
Answer:
The speed of combined package after the collision is [tex]\frac{\sqrt(2gh)}{4}\\[/tex].
Explanation:
mass of first package = m
height , h = 3 m
mass of second package = 3 m
let the speed of first package is u as it strikes with the second package.
Use the third equation of motion
[tex]v^2 = u^2 + 2 gh \\\\u^2 = 0 + 2 g h \\\\u = \sqrt {2gh}[/tex]
Let the velocity of combined package after the collision is v.
Use the conservation of momentum
[tex]m\times u + 3m \times 0= (m + 3m)\times v\\\\m u = 4mv \\\\v=\frac {u}{4}\\\\v = \frac{\sqrt(2gh)}{4}\\\\[/tex]
a 250 mH coil of negligible resistance is connected to an AC circuit in which as effective current of 5 mA is flowing. if the frequency is 850Hz, find the inductive reactance
Answer:
the inductive reactance of the coil is 1335.35 Ω
Explanation:
Given;
inductance of the coil, L = 250 mH = 0.25 H
effective current through the coil, I = 5 mA
frequency of the coil, f = 850 Hz
The inductive reactance of the coil is calculated as;
[tex]X_l = \omega L = 2\pi f L\\\\X_l = 2\pi \times 850 \times 0.25\\\\X_l = 1335.35 \ ohms[/tex]
Therefore, the inductive reactance of the coil is 1335.35 Ω
What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 555 nmnm
Answer:
The minimum thickness of soap film is [tex]2.086\times 10^{-7} m[/tex].
Explanation:
wavelength = 555 nm
refractive index, n = 1.33
For the destructive interference,
the thickness is given by
[tex]t =\frac{m \lambda }{2 n}[/tex]
Here, m is the order, n is the refractive index and [tex]\lambda[/tex] is the wavelength.
For minimum thickness, m = 1
So the thickness is
[tex]t =\frac{1 \times 555\times 10^{-9} }{2 \times 1.33}\\\\t = 2.086\times 10^{-7} m[/tex]
Subtract the following numbers, using scientific notation and the correct number of significant digits.
6.94 × 103 mm - 4.5 × 102 mm = _____.
2.4 × 103 mm
2.44 × 102mm
6.49 × 103 mm
6.5 × 103 mm
Answer:
The correct answer is - 6.49 × 10^3 mm.
Explanation:
The correct scientific notation of the given subtraction problem is:
6.94 × 10^3 mm - 4.5 × 10^2 mm = _____.
The correct number of significant digits is
a. 6.94 × 10^3 mm = 3
b. 4.5 × 10^2 mm = 2
So subtracting the 6.94 × 10^3 mm - 4.5 × 10^2 mm
= 6940 - 450
= 6.49× 10^3 mm.
Answer:
6.5x 10^3 mm
Explanation:
A system consists of a gas in an enclosed cylinder attached to a movable piston. The system is initially at 63 L and then is compressed to 31 liters. Determine the sign of work. Will it be a negative or positive
Answer:
The sign of work will be negative.
Explanation:
The work of the system is given by:
[tex] W = _{V_{i}}^{V_{f}}\int pdV = p(V_{f} - V_{i}) [/tex]
Where:
[tex]V_{f}[/tex]: is the final volume = 31 L
[tex]V_{i}[/tex]: is the initial volume = 63 L
p: is the pressure
Even though we do not have the pressure value, by knowing the values of the initial and final volume we can predict the sign of work.
[tex] W = p(V_{f} - V_{i}) = p(31 L - 63 L) = -32p [/tex]
Therefore, the sign of work will be negative.
I hope it helps you!
Ftension
120 N
10 kg
Fg
What is the net force on the box?
O 22 Newtons upward
120 Newtons upward
O 98 Newtons downward
O O Newtons
Answer:
120N Hacia arriba
A rubber ball is shot straight up from the ground with a speed of 12 m/s. Simultaneously, a second identical rubber ball is dropped from rest exactly 7 m directly above the first ball. At what height (in m) do the two balls collide?
Answer:
6.17 m
Explanation:
We are given that
Initial speed of rubber ball, u=12 m/s
Total height, h=7 m
Initial speed of second ball, u'=0
We have to find the height at which the two balls collide.
Let first rubber ball and second ball strikes after t time.
For first ball
Distance traveled by first ball in time t
[tex]S=ut-\frac{1}{2}gt^2[/tex]
Substitute the value
[tex]S=12t-\frac{1}{2}(9.8)t^2[/tex]
[tex]S=12t-4.9t^2[/tex] ...(1)
Distance traveled by second ball in time t
[tex]7-S=\frac{1}{2}(9.8)t^2[/tex]
[tex]7-S=4.9t^2[/tex] .....(2)
Using equation (2) in equation (1) we get
[tex]S=12t-(7-S)[/tex]
[tex]S=12t-7+S[/tex]
[tex]\implies 12t=7[/tex]
[tex]t=\frac{12}{7}[/tex]sec
Now, using the value of t
[tex]S=12(\frac{12}{7})-4.9(\frac{12}{7})^2[/tex]
S=6.17 m
Hence, at height 6.17 m the two balls collide .
what is parallelogram law of vector addition ???
Answer:
According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex
Explanation:
Explain the phenomenon and change in potential energy
Answer:
Explanation:
The change in potential is then defined as the negative of the work done by that force. ... You can't have work done by gravity AND a change in gravitational potential energy. You have to do it one way or the other. This means that the most important step in solving work-energy problems is choosing a system.
the phenomenon is An object that has potential energy can transfer that energy into kinetic energy when the object begins to move, due to its mass or position. For example, a person jumping on a trampoline has potential energy when they reach the peak of a jump, and their force changes direction from upward to downward.