Answer:
D) I and IV
Explanation:
A closed system is the one where mass can not enter or leave the system, while the energy can enter o leave the system.
I. This is true according to the definition. Because only energy can enter or leave a closed system.
II. This is not true. Because mass interaction is not allowed in a closed system.
III. This is false. Because energy exchange is allowed.
IV. True. Because energy exchange is possible.
Therefore the correct option is:
D) I and IV
If the output work of a simple machine equals the input work, the machine is said to have ______ efficiency.
If the output work of a simple machine equals the input work, the machine is said to have 100% efficiency.
[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]
In an old Sesame Street skit, Kermit the Frog interviewed a local resident on the planet Koozebane, who measures time in gleeps and distance in glorps. One glorp is defined as the distance a rock will fall from rest in one gleep. How far will a rock fall from rest during the second gleep
Answer:
four glorps
Explanation:
We know :
[tex]$y=v_{0y}t + \frac{1}{2}a_yt^2$[/tex]
[tex]$\Rightarrow -1 \text{glorp} = 0 - \frac{g}{2} \times (1 g\text{ gleep})^2$[/tex]
[tex]$\Rightarrow 1 \text{ glorp}= \frac{g}{2} (1 \text{ gleep})^2$[/tex] .............(i)
Now, t' = 2 gleep
[tex]$y=v_{0y}t + \frac{1}{2}a_yt^2$[/tex]
[tex]$=0+ \frac{-g}{2} (2 \text{ gleep})^2$[/tex]
[tex]$=-\frac{4g}{2}(2 \text{ gleep})^2$[/tex]
[tex]$=4\left[\frac{-g}{2} (\text{gleep})^2\right]$[/tex]
= 4 (-1 gleep) (From (i))
So, |y| = 4 glorp
Copper wires are used as connecting wires because
(1 Point)
Copper has very high melting point
Copper wires are very thick wires
Copper wire offers a lower resistance
Copper wire has an attractive colour
[tex]\huge{ \mathfrak{ \underline{ Answer }\: \: ✓ }}[/tex]
Copper wires are used as connecting wires in circuits because they offer very less resistance.
__________________________________________________________
[tex]\mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]
the caste system is an example of
Answer:
It is example of Closed system
Imagine you are holding a box in your hand, the force required for you to hold the box with mass 4.54kg and you want to accelerate the box 2m/s2. Move the box in your hand a) upward vertically, b) downward vertically, and c) horizontally. Calculate the magnitudes of forces in the x and y direction.
Answer:
(a) Fₓ = 0 N
[tex]F_y[/tex] = 9.08 N
(b)
(a) Fₓ = 0 N
[tex]F_y[/tex] = 9.08 N
(c) [tex]F_y[/tex] = 0 N
Fₓ = 9.08 N
Explanation:
The magnitude of the force will remain the same in each case, which is given as follows:
F = ma (Newton's Second Law)
where,
F = force = ?
m = mass = 4.54 kg
a = acceleration = 2 m/s²
Therefore,
F = (4.54 kg)(2 m/s²)
F = 9.08 N
Now, we come to each scenario:
(a)
Since the motion is in the vertical direction. Therefore the magnitude of the force in x-direction will be zero:
Fₓ = 0 N
For upward direction the force will be positive:
[tex]F_y[/tex] = 9.08 N
(b)
Since the motion is in the vertical direction. Therefore the magnitude of the force in x-direction will be zero:
Fₓ = 0 N
For upward direction the force will be negative:
[tex]F_y[/tex] = - 9.08 N
(c)
Since the motion is in the horizontal direction. Therefore the magnitude of the force in y-direction will be zero:
[tex]F_y[/tex] = 0 N
Fₓ = 9.08 N
1. Pam has a mass of 48.3 kg and she is at rest on
smooth, level, frictionless ice. Pam straps on
a rocket pack. The rocket supplies a constant
force for 27.3 m and Pam acquires a speed of
62 m/s.
What is the magnitude of the force?
Answer in units of N.
2. What is Pam’s final kinetic energy?
Answer in units of J.
3. A child and sled with a combined mass of 55.7
kg slide down a frictionless hill that is 11.3 m
high at an angle of 29 ◦
from horizontal.
The acceleration of gravity is 9.81 m/s
3. If the sled starts from rest, what is its speed
at the bottom of the hill?
Answer in units of m/s
Answer:
1. F = 3400 N = 3.4 KN
2. [tex]K.E_f=92832.6\ J = 92.83\ KJ[/tex]
3. v = 14.9 m/s
Explanation:
1.
First, we will calculate the acceleration of Pam by using the third equation of motion:
[tex]2as = v_f^2-v_i^2[/tex]
where,
a = acceleration = ?
s = distance = 27.3 m
vf = final speed = 62 m/s
vi = initial speed = 0 m/s
Therefore,
[tex]2a(27.3\ m) = (62\ m/s)^2-(0\ m/s)^2\\\\a = 70.4\ m/s^2[/tex]
Now, we will calculate the force by using Newton's Second Law of Motion:
F = ma
F = (48.3 kg)(70.4 m/s²)
F = 3400 N = 3.4 KN
2.
Final kinetic energy is given as:
[tex]K.E_f = \frac{1}{2}mv_f^2\\\\K.E_f = \frac{1}{2} (48.3\ kg)(62\ m/s)^2[/tex]
[tex]K.E_f=92832.6\ J = 92.83\ KJ[/tex]
3.
According to the law of conservation of energy:
[tex]Potential\ Energy\ at\ top = Kinetic\ Energy\ at\ bottom\\mgh = \frac{1}{2}mv_2 \\\\v = \sqrt{2gh}[/tex]
where,
v = speed at bottom = ?
g = acceleration due to gravity = 9.81 m/s²
h = height at top = 11.3 m
Therefore,
[tex]v = \sqrt{(2)(9.81\ m/s^2)(11.3\ m)}[/tex]
v = 14.9 m/s
If a 4 Ohm resistor and a 12 Ohm resistor are connected in parallel, what is the total
resistance?
Rt = 3 ohms
Explanation:
Let R1 = 4-ohm resistor
R2 = 12-ohm resistor
For 2 resistors connected in parallel, the total resistance Rt is given by
1/Rt = 1/R1 + 1/R2
or
Rt = R1R2/(R1 + R2)
= (4 ohms)(12 ohms)/(4 ohms + 12 ohms)
= 48 ohms^2/16 ohms
= 3 ohms
WILL GIVE BRAINLIEST
Two long anti-parallel current-carrying wires carry currents of 20 A and 5.0 A. If the wires are separated by 20 cm. Find the magnitude of the magnetic field a point equally separated between both wires.
Answer:
5 x 10⁻⁵ T
Explanation:
Magnetic field at a point d distance away from a current carrying wire having current of I
B = 10⁻⁷ x 2I / d
Here magnetic field due to current of 20 A
B₁ = 10⁻⁷ x 2 x 20 / 10 x 10⁻²
= 4 x 10⁻⁵ T .
Here magnetic field due to current of 5 A
B₂ = 10⁻⁷ x 2 x 5 / 10 x 10⁻²
= 10⁻⁵ T .
These magnetic fields are acting in the same direction
Total magnetic field
B = B₁ + B₂
= 4 x 10⁻⁵ + 10⁻⁵ = 5 x 10⁻⁵ T .
A 0.14-km wide river flows with a uniform speed of 4.0 m/s toward the east. It takes 20 s for a boat to cross the river to a point directly north of its departure point on the south bank. What is the speed of the boat relative to the water
Answer:
The right approach is "8.1 m/s". A further explanation is provided below.
Explanation:
According to the table,
Speed of Boat
= [tex]\frac{s}{t}[/tex]
[tex]V_b=\frac{140}{20}[/tex]
[tex]V_a = 4 \ m/s[/tex]
[tex]V_B = 7 \ m/s[/tex]
Now,
⇒ [tex](V_{relative})^2 = (7)^2+(4)^2[/tex]
or,
⇒ [tex](V_r)^2=49+16[/tex]
[tex]=65[/tex]
[tex]V_r=\sqrt{65}[/tex]
[tex]=8.1 \ m/s[/tex]
What is pressure in physics
Help me with this please
Answer:
check out of phase
Explanation:
this is my answer
A bell is ringing inside of a sealed glass jar that is connected to a vacuum pump. Initially, the jar is filled with air. What does one hear as the air is slowly removed from the jar by the pump
Answer:
See Explanation
Explanation:
Sound is a mechanical wave. A mechanical wave requires a material medium for propagation. This means that sound waves must be carried in air. If there are no air molecules, sound waves can not travel.
When air is gradually removed from the jar by the pump, the sound intensity from the bell gradually decreases owing to the fact that air which is the medium through which sound waves are propagated is gradually being removed from the jar.
Could anyone help me on this question?
You really don't need any help on the question. It's all right there in the picture. What you need help with is the answer.
The number of times the same thing happens each second is called its "frequency". The frequency of the dragonfly's flaps is 477 Hz. (If you're close enough to the dragonfly, you can hear the wings flapping. It sounds like a raspy tone with a frequency of 477 Hz.)
The "period" is just the length of time it takes to happen once. That length of time is just (1 / frequency) .
The dragonfly flaps its wings once every (1 / 477 Hz) = 0.0021 second (C)
source of sinusoidal electromagnetic waves radiates uniformly in all directions. At a distance of 10.0 m from this source, the amplitude of the electric field is measured to be 3.50 N>C. What is the electric-field amplitude 20.0 cm from the source
Answer:
[tex]175\ \text{N/C}[/tex]
Explanation:
[tex]E_1[/tex] = Initial electric field = 3.5 N/C
[tex]E_2[/tex] = Final electric field
[tex]r_1[/tex] = Initial distance = 10 m
[tex]r_2[/tex] = Final distance = 20 cm
Electric field is given by
[tex]E=\sqrt{\dfrac{2P}{\pi r^2c\varepsilon_0}}[/tex]
So,
[tex]E\propto \dfrac{1}{r}[/tex]
[tex]\dfrac{E_2}{E_1}=\dfrac{r_1}{r_2}\\\Rightarrow E_2=E_1\dfrac{r_1}{r_2}\\\Rightarrow E_2=3.5\dfrac{10}{0.2}\\\Rightarrow E_2=175\ \text{N/C}[/tex]
The electric field amplitude at the required point is [tex]175\ \text{N/C}[/tex].
A 0.413 kg block requires 1.09 N
of force to overcome static
friction. What is the coefficient
of static friction?
(No unit)
PLEASE HELP!
Answer:
static friction=0.126
Help me with this please
Answer:
yong may check po ayon yong sagot
You purchase a motor in Germany designed to run at 415 Volts, 50 Hz. It has 75 kW output power, runs at 2978 RPM and has 240 N-m of rated torque. You ship it Canada and run it at 480 Volts, 60 Hz. What will be the new torque in N-m
Answer:
230N-m
Explanation:
Given data
Power P= 75kW
Frequency f= 60Hz
w= 2πf
w=2*π*60
w=120π rad/s
Power= T*w
Power= IV= 415*I
75*10^3= 415*I
I=180.72 A
V= 480V
Power= 180.72*480
Power= 86.746kW
Power= 86.746= T*120π
T= 120π/86.746
T= 230N-m
Which of the following least represents an negative impact on Earth caused mostly by humans?
A) Deforestation
B) Urbanization
C) Erosion
D) Recycling
Answer:
A
Explanation:
because uhhh I'm doing the same test as you kinda LOL
Moving current has electrical energy.
. A small car of mass m and a large car of mass 2m drive around a highway curve of radius R. Both cars travel at the same speed (v). The
centripetal acceleration (Grad) of the large car is the centripetal acceleration of the small car.
four times
twice
half
equal to
Complete question is;
A small car of mass m and a large car of mass 2m drive around a highway curve of radius R. Both cars travel at the same speed (v). The
centripetal acceleration (Grad) of the large car is the centripetal acceleration of the small car. How does the Force of the small car FS compare to the force of the large car FL as they round the curve.
four times
twice
half
equal to
Answer:
Half
Explanation:
Formula for centripetal force is given as;
F = mv²/R
Where;
v is velocity
R is radius
Now, centripetal acceleration is given by;
a = v²/R
Since they both travel with the same velocity V and radius remains the same, we can say that;
F = ma
For the small car;
FS = ma
For the big car;
FL = 2ma
This means the force of the small car is half of that of the Large car
Thus;
FS = ½FL
9. Cellular respiration occurs in what types of cells?
Answer:
Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria
Explanation:
Cellular respiration takes place in the cells of all organisms. It happening in autotrophs such as plantas as well as heterotrophs such as animals. Cellular respiration starts in the cytoplasm of cells.
It is finished in mitochondria.
The door is 2 m tall. How tall is it in inches? Note: There are 2.54 cm in 1 inch.
A. 78.7 in
B. 500 in
C. 787.4 in
D. 201.4 in
Answer:
Height of the door = 2m = 2000 cm
1 in = 2.54 cm
So 1 cm = 1/2.54 in
2000 cm = 200000/ 254
=
787.401574803
So no.c is correct
The door is 78.7 inch tall. Hence, option (A) is correct.
What is unit of length?Any arbitrarily selected and widely used reference standard for length measurement is referred to as a unit of length. The metric system, which is adopted by every nation on earth, is the most widely utilized in modern times.
The American customary units are also in use in the United States. In the UK and several other nations, British Imperial units are still used sometimes. There are SI units and non-SI units in the metric system.
Given that: the height of the door is = 2 meter
= 2*100 centimeter
= 200 centimeter.
There are 2.54 centimeter in 1 inch.
Hence, the height of the door is = 2 meter = 200 centimeter
= (200/2.54) inch
= 78.7 inch.
The door is 78.7 inch tall.
Learn more about length here:
https://brainly.com/question/17139363
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Suppose you walk 18.0 m straight west and then 25.0 m straight north. How far are you from your starting point and what is the compass direction of a line connecting your starting point to your final position
Answer:
H = 30.8 m
Explanation:
Its a lot to write down so I'm not going to but if you want the answer just reply to this and say you need the answer. Thanks.
David is driving a steady 30.0 m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.10 m/s2 at the instant when David passes. Part A How far does Tina drive before passing David
Answer:
Explanation:
Let after time t , Tina catches up David .
Distance travelled by them are equal ,
Distance travelled by Tina
s = ut + 1/2 a t²
= .5 x 2.10 t²
= 1.05 t²
Distance travelled by David
= 30 t ( because of uniform velocity )
1.05 t² = 30t
t = 28.57 s
Distance travelled by Tina
= 1/2 a t²
= .5 x 2.10 x 28.57²
= 857 m approx.
Answer: [tex]857\ m[/tex]
Explanation:
Given
Speed of David car [tex]v=30\ m/s[/tex]
Tina begins to accelerate [tex]2.1\ m/s^2[/tex] after David pass the tina
Suppose it took t time for tina to catch David
Distance traveled by David in t time
[tex]\Rightarrow s_d=30\times t[/tex]
Using the equation of motion to get the distance of Tina is
[tex]s_t=ut+\dfrac{1}{2}at^2\\\\s_t=0+\dfrac{1}{2}\times 2.1t^2[/tex]
now, [tex]s_d=s_t[/tex]
[tex]30t=\dfrac{2.1}{2}t^2\\\\\Rightarrow 2.1t^2-60t=0\\\Rightarrow t(2.1t-60)=0\\\Rightarrow t=0,28.57\ s[/tex]
Neglecting [tex]t=0[/tex]
Distance traveled by tina in [tex]28.57\ s[/tex] is
[tex]s_t=\dfrac{1}{2}\times 2.1\times (28.57)^2\\\\s_t=857.057\approx 857\ m[/tex]
A wind turbine is rotating 5.98 rad/s when the wind abruptly stops blowing. It takes the turbine 27.5s to stop rotating. how many revolutions does his turbine make before it comes to a stop
Answer:
S = Vo t * 1/2 a t^2 equation for distance traveled
w = w0 t + 1/2 a t^2 equivalent circular equation where w equals omega
w = 5.98 * 27.5 + a (27.5)^2/ 2
a = (w2 - w1) / t = -5.98 / 27.5 = -.217
w = 5.98 * 27.5 - 1/2 * .217 * 27.5^2 = 82.4
Since 1 Rev = 2 pi radians
Rev = 82.4 / 2 * pi = 13.1 Rev
cellus
Find the x-component of this
vector:
92.5 m
32.0
Explanation:
x-component:
Vx = Vcos(theta)
= (92.5 m)cos(32.0)
= 78.4 m
Answer:
-78.4
Explanation:
For acellus students
A body weighing 250 grams was dropped from a helicopter flying at an altitude of 100 meters. Determine the potential energy of this body. (g = 10 m/s² ). PLEASE HURRY ITS A TEST
[tex]\huge{ \mathfrak{ \underline{question : }}}[/tex]
A body weighing 250 grams was dropped from a helicopter flying at an altitude of 100 meters. Determine the potential energy of this body.
[tex] \huge{ \mathfrak{given : }}[/tex]
mass = [tex] 0.250 kg[/tex]acceleration = [tex] 10 m/s^2 [/tex]height = [tex] 100 m [/tex][tex]\huge{ \mathfrak{ \underline{ Answer \: \: ✓ }}}[/tex]
[tex] \boxed{ \mathbf{potential \: \: energy = mgh}}[/tex]
[tex] 0.250 \times 10 \times 100[/tex][tex] {250}{} [/tex]potential energy = 250 joules
[tex] \#TeeNForeveR[/tex]
What can be the maximum value of the original kinetic energy of disk AA so as not to exceed the maximum allowed value of the thermal energy
The question is incomplete. The complete question is :
In your job as a mechanical engineer you are designing a flywheel and clutch-plate system. Disk A is made of a lighter material than disk B, and the moment of inertia of disk A about the shaft is one-third that of disk B. The moment of inertia of the shaft is negligible. With the clutch disconnected, A is brought up to an angular speed ?0; B is initially at rest. The accelerating torque is then removed from A, and A is coupled to B. (Ignore bearing friction.) The design specifications allow for a maximum of 2300 J of thermal energy to be developed when the connection is made. What can be the maximum value of the original kinetic energy of disk A so as not to exceed the maximum allowed value of the thermal energy?
Solution :
Let M.I. of disk A = [tex]$I_0$[/tex]
So, M.I. of disk B = [tex]$3I_0$[/tex]
Angular velocity of A = [tex]$\omega_0$[/tex]
So the kinetic energy of the disk A = [tex]$\frac{1}{2}I_0\omega^2$[/tex]
After coupling, the angular velocity of both the disks will be equal to ω.
Angular momentum will be conserved.
So,
[tex]$I_0\omega_0 = I_0 \omega + 3I_0 \omega$[/tex]
[tex]$I_0\omega_0 = 4I_0 \omega$[/tex]
[tex]$\omega = \frac{\omega_0}{4}$[/tex]
Now,
[tex]$K.E. = \frac{1}{2}I_0\omega^2+ \frac{1}{2}3I_0\omega^2$[/tex]
[tex]$K.E. = \frac{1}{2}I_0\frac{\omega_0^2}{16}+ \frac{1}{2}3I_0\frac{\omega_0^2}{16}$[/tex]
[tex]$K.E. = \frac{1}{2}I_0\omega_0^2 \left(\frac{1}{16}+\frac{3}{16}\right)$[/tex]
[tex]$K.E. = \frac{1}{2}I_0\omega_0^2\times \frac{1}{4}$[/tex]
[tex]$\Delta K = \frac{1}{2}I_0\omega_0^2 - \frac{1}{2}I_0\omega_0^2 \times \frac{1}{4} $[/tex]
[tex]$2300=\frac{3}{4}\left(\frac{1}{2}I_0\omega_0^2\right)$[/tex]
[tex]$\frac{1}{2}I_0\omega_0^2=2300 \times \frac{4}{3 } \ J $[/tex]
Therefore, the maximum initial K.E. = 3066.67 J
I’ll give Brainliest, Identify the force acting as the
centripetal force when a car circulates
around a flat circular track
Friction
Gravitation
Normal
tension
Answer:
Friction hope this helps <3