Answer: the answer is a
Explanation:
According to Coulomb's Law, how does distance affect the electric force?
A. The electric force only acts on objects that are in contact with
each other.
B. Only in charging by induction can the electric force act at a
distance.
C. Electric force gets stronger as charges get closer together and
gets weaker as charges move farther apart.
D. The electric force is zero if the objects are more than several
centimeters apart.
Answer:
C option is right.
Explanation:
According to columb's law
F ∝ 1/r²
so as r means distance between charges decrease force F increase and vice versa.
58) Two balls, A and B are simultaneously projected from the top
of a building at 10 mis upwards & 20 m/s downwards respectively. Find
out the separation btwn them 3 sec after projection.
Answer:
90 m
Explanation:
For ball A::
The equation of a ball moving upwards is given by the formula:
s = ut - (1/2)gt²
where u is the initial velocity, t is the time covered, g is the acceleration due to gravity = 10 m/s² and s is the distance travelled.
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) - (1/2) * 10 * 3²
s = 30 - 45
s = -15 m
The negative sign means the object travels in the opposite direction. Hence s = 15 m
For ball B::
The equation of a ball falling downwards is given by the formula:
s = ut + (1/2)gt²
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) + (1/2) * 10 * 3²
s = 30 + 45
s = 75 m
Hence the separation between the two balls after 3 sec of projection = 15 m + 75 m = 90 m
The student wants to collect data to determine the work done by the force due to gravity on the object as it falls. Which of the following lists contains the fewest number of measuring devices, in addition to the motion detector, that the student can use?
A - spring scale
B - spring scale and meterstick
C - stopwatch and meterstick
D - spring scale, meterstick, and stopwatch
Answer:
B - spring scale and meterstick
Explanation:
The work done by the force of gravity as the object falls is equal to the potential energy of the object.
We know that the gravitational potential energy(PE) of an object is obtained by;
PE =mgΔh
Where;
m = mass of the object
g = acceleration due to gravity
h= height of the object
The spring scale is needed to measure the mass of the object while the meterstick measures the Δh in meters.
Answer:
B
Explanation:
w= fd
f: spring scale
d: meterstick
Drop a comment if you have any questions! :)
Which observation is the best evidence that some colors of visible light are
being absorbed in this photo?
A. The man's head is distorted under the water.
B. The top of the man's head appears disconnected.
C. The shape of the man's arm is clearly seen underwater.
D. The snorkel in the man's mouth appears yellow.
Answer:
D-The snorkel in the mans mouth appears yellow
Explanation:
Answer D is the only example related visible light being absorbed.
An object on the end of a spring with spring constant k moves in simple harmonic motion with amplitude A and frequency f. Which of the following is a possible expression for the kinetic energy of the object as a function of time t?
a. kA^2sin^(2πft)
b. 1/2kA^2cos^2(2πft)
c. 1/2kA sin(2πft)
d. kAcos(2πft)
e. 1/2kAsin(2πft)
The expression for the kinetic energy of the object as a function of time, t is [tex]K.E = \frac{1}{2} k A^2 \ cos^2 \ (2\pi ft)[/tex].
The general wave equation is given as;
[tex]x = A \ cso(\omega t)\\\\x = A \ cos(2 \pi ft)[/tex]
Apply the principle of conservation of energy, the kinetic energy of a particle in such motion is given as;
[tex]K.E = U_x\\\\K.E = \frac{1}{2} kx^2[/tex]
Substitute the value of x into the kinetic energy equation
[tex]K.E = \frac{1}{2} kx^2\\\\K.E = \frac{1}{2} k ( A \ cos (2\pi ft)^2\\\\K.E = \frac{1}{2} k A^2 \ cos^2 \ (2\pi ft)[/tex]
Thus, the expression for the kinetic energy of the object as a function of time, t is [tex]K.E = \frac{1}{2} k A^2 \ cos^2 \ (2\pi ft)[/tex].
Learn more here:https://brainly.com/question/13736293
Please help with a simple Physics question!
Regions of compression and rarefaction help define ______.
a. electromagnetic waves
b. longitudinal waves, but not transverse waves
c. transverse waves, but not longitudinal waves
d. all mechanical waves
SERIOUS ANSWERS PLEASE, THANK YOU AND GOD BLESS
Compression- a region in a longitudinal (sound) wave where the particles are closest together. Rarefaction- a region in a longitudinal (sound) wave where the particles are furthest apart. Wave motion and particles.
Answer is B.
A 0.5 kg rock is dropped from a height of 1.0 m above the ground. Approximately how much kinetic energy will be stored in the rock after it has fallen halfway to the ground.
Answer:
2.45 J
Explanation:
The following data were obtained from the question:
Mass (m) = 0.5 kg
Height (h) = 1 m
Kinetic energy (KE) =?
Next, we shall determine the velocity of the rock after it has fallen half way. This can be obtained as follow:
Initial velocity (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) = 1/2 = 0.5 m
Final velocity (v) =?
v² = u² + 2gh
v² = 0² + (2 × 9.8 × 0.5)
v² = 9.8
Take the square root of both side
v = √9.8
v = 3.13 m/s
Finally, we shall determine the kinetic energy of the rock after it has fallen half way. This can be obtained as follow:
Mass (m) = 0.5 kg
Velocity (v) = 3.13 m/s
Kinetic energy (KE) =?
KE = ½mv²
KE = ½ × 0.5 × 3.13²
KE = 0.25 × 9.8
KE = 2.45 J
Therefore, the kinetic energy of the rock after it has fallen half way is 2.45 J
a uniform rod is hung at onen end and is partially submerged in water. If the density of the rod is 5/9 than of wter, find the fraction of the legth tof the rod above water
Answer:
[tex]\frac{h_{liquid} }{ h_{body} }[/tex] = 5/9
Explanation:
This is an exercise that we can solve using Archimedes' principle which states that the thrust is equal to the weight of the desalted liquid.
B = ρ_liquid g V_liquid
let's write the translational equilibrium condition
B - W = 0
let's use the definition of density
ρ_body = m / V_body
m = ρ_body V_body
W = ρ_body V_body g
we substitute
ρ_liquid g V_liquid = ρ_body g V_body
[tex]\frac{\rho_{body} }{\rho_{liquid} } } = \frac{V_{liquid} }{V_{body} } }[/tex]
In the problem they indicate that the ratio of densities is 5/9, we write the volume of the bar
V = A h_bogy
Thus
[tex]\frac{V_{liquid} }{V_{1body} } = \frac{ h_{liquid} }{h_{body} }[/tex]
we substitute
5/9 = [tex]\frac{h_{liquid} }{ h_{body} }[/tex]
A man walks 10 km north, turns around and walks 5 km south. What displacement did the man walk?
A. 10km S
B. 5km N
C. 15km N
D. 5km S
Answer:
The total displacement is 5 km North (answer B)
Explanation:
Recall that displacement is defined by the vector formula:
Displacement = Final position - initial position
Which corresponds to a vector with its tail at the starting point, and the arrow at the final position. This gives a vector pointing North, and of length 5 km.
This agrees with answer labeled B.
An 80kg astronaut traveled to the moon, where gravity is one-sixth (116) as
strong as Earth's gravity. What is the astronaut's weight on the moon?
F=mg.g=(1/6)(9.8m/s?)
Answer:
Wmoon = 131 [N]
Explanation:
We know that the weight of a body is equal to the product of mass by gravitational acceleration.
Since we are told that the gravitational acceleration of the moon is equal to one-sixth of the acceleration of Earth's gravitation. Then we must multiply the value of Earth's gravitation by one-sixth.
[tex]w_{moon}=\frac{1}{6} *m*g\\w_{moon}=\frac{1}{6} *80*9.81\\w_{moon}=130.8 [N] = 131 [N][/tex]
When Pluto was classified as a planet it was known as a oddball planet why? Why is it less if an oddball now?
Answer:
a strange world that has baffled scientists ever since it was discovered in 1930. It is not the large gas giant that one might expect to find in the outer reaches of the solar system.
Explanation:
Explanation
A child pulls a wagon at a constant velocity of 4.0 m/s for 4.0 minutes along a level sidewalk. The child does this applying a 22 N force to the wagon handle, which is inclined at 35 ° to the sidewalk as shown below. How much work does the child do on the wagon ?
288 k J
8.7 kJ
17.3 kJ
2.3 kJ
Answer:
288kj
Explanation:
Jane climbs the stairs to the first floor all by herself in a certain time. If the next time she rides the elevator to the first floor then which of the following statements is true?
The work done in both cases are different
the time taken in both cases is the same
the power in both cases is the same.
the work done in both cases is the same.
Answer:
the power in both cases is the same.
Explanation:
hope helps you
thanksss
1. Each of four boys were given
some marbles.
have
day.
punc
exan
class
Joe: sixth multiple of eight
Khal: quarter of a gross
mar
Tate: 4 dozen
Tevin: one score plus a dozen
Which two boys r3eceived the same
number of marbles?
A. Joe and Tate
B. Joe and Khal
C. Tate and Tevin
D. Joe and Tevin
Answer:
the answer is A because
from tate 4 dozen is 48 and from joe the sixth multiple of eight is 48
When you mix two substances, the heat gained by one substance is equalto the heat lost by the other substance. Suppose you place 125 g of aluminum ina calorimeter with 1,000 g of water. The water changes temperature by 2 °C andthe aluminum changes temperature by â74.95 °C.
Required:
a. Water has a known specific heat capacity of 4.184 J/g °C. Usethe specific heat equation to find out how much heat energy the watergained (q).
b. Assume that the heat energy gained by the water is equal to the heat energy lost by the aluminum. Use the specific heat equation to solve for the specific heat of aluminum. (Hint: Because heat energy is lost, the value of q is negative.)
Answer:
A) 8,368 J
B) 0.893 J/gºC
Explanation:
A)
The heat gained by the water can be obtained solving the following equation:[tex]q_{g} = c_{w} * m * \Delta T (1)[/tex]
where cw = specific heat of water = 4.184 J/gºCm= mass of water = 1,000 gΔT = 2ºC Replacing these values in (1) we get:[tex]q_{g} = c_{w} * m * \Delta T = 4.184 J/gºC*1,000 g* 2ºC = 8,368 J (2)[/tex]
B)
Assuming that the heat energy gained by the water is equal to the one lost by the aluminum, we can use the same equation, taking into account that the energy is lost by the aluminum, so the sign is negative: -8,368 J.Replacing by the mass of aluminum (125 g), and the change in temperature (-74.95ºC), in (1), we can solve for the specific heat of aluminum, as follows:[tex]q_{l} = c_{Al} * m_{Al} * \Delta T (3)[/tex]
⇒ [tex]-8,368 J = c_{Al}* 125 g * (-74.95ºC) (4)[/tex]
[tex]c_{Al} = \frac{-8,368J}{125g*(-74.95ºC} = 0.893 J/gºC (5)[/tex]
Answer:
A: the heat gained is 8368 J (8.368 KJ)
B: 0.893 J/g°C
Explanation:
A:
q = ?
m = 1000 g
C = 4.184 J/g°C
△T = 2°C
q = mc△T
q = (1000g) (4.184 J/g °C) (2 °C)
q = 8368 J
B:
q = mc△T
---------------
△T △T
c = q / m△T
c = - 8368 J / (125 g) (-74.95 °C)
c = 0.893 J/g°C
John is conducting an experiment that involves melting ice cubes. Which of the following is most important for John to collect reliable data?
A.The outcome needs to be controlled.
B.An unbiased observer must witness the experiment.
C.Technology needs to be used to determine the results.
D.Only one variable should be tested during the experiment.
Answer:
Hmmmm
Explanation:
Answer:
B
Explanation:
Which hormone is released by the pancreas to reduce blood glucose levels?
Glucagon
Insulin
Glycogen
Answer:
Insulin.
Explanation:
The most important hormone that the pancreas produces is insulin. Insulin is released by the 'beta cells' in the islets of Langerhans in response to food. Its role is to lower glucose levels in the bloodstream and promote the storage of glucose in fat, muscle, liver and other body tissues.
Once again, move the balloon to the right and let it go. Note how fast the balloon moves. Next, brush the balloon against the entire sweater. Allow all the electrons to transfer. Again, move the balloon all the way to the right, let it go, and note how fast it moves. Is there a difference in how fast the balloon moves when the balloon has more electrons and the sweater has fewer electrons?
Answer:
Yes. The balloon moves faster when it has more electrons and the sweater has fewer electrons
Explanation:
From Plato. Hope this helps!
Answer:
Yes. The balloon moves faster when it has more electrons and the sweater has fewer electrons
Explanation:
Edmentum
importance of choke coil?
Answer:The choke coil works because it can act as an inductor. When the current pass through will change as AC currents creates a magnetic field in the coil that works against that current. This is known as inductance and blocks most of the AC current from passing through.
Explanation:
Need help to get this question right!!
Answer:
16 times as strong
Explanation:
From the question given above, the following assumptions were made:
Initial Force (F₁) = F
Initial distance apart (r₁) = r
Final distance apart (r₂) = ¼r
Final force (F₂) =?
Next, we shall obtain a relationship between the force and the distance apart. This can be obtained as follow:
F = GM₁M₂ / r²
Cross multiply
Fr² = GM₁M₂
If G, M₁ and M₂ are kept constant, then,
F₁r₁² = F₂r₂²
Finally, we determine the new force as follow:
Initial Force (F₁) = F
Initial distance apart (r₁) = r
Final distance apart (r₂) = ¼r
Final force (F₂) =?
Fr² = F₂ × (¼r)²
Fr² = F₂ × r²/16
Fr² = F₂r² / 16
Cross multiply
16Fr² = F₂r²
Divide both side by r²
F₂ = 16Fr² / r²
F₂ = 16F
From the calculations made above, we can see that the new force is 16 times the original force.
Thus, the new force is 16 times stronger.
If a student wishes to conduct an experiment to prove the conservation of momentum between two colliding objects, what are the minimum quanitities the student must record in order to complete this experiment and explain why you think they must record those.
look at the diagram below
Which statement is correct about Ray 1?
The asteroid Icarus orbits the sun like other planets. Its period is about 410 days. What is its mean distance from the sun
Answer:
Mean distance = 1.61 x 10^8 km
Explanation:
Given the following data;
Orbital period for Icarus, T2 = 410 days
To find the mean distance of Icarus, we would use Kepler's third law of motion.
According to Kepler's third law of planetary motion, the square of any planetary body's orbital period (P) is directly proportional to the cube of its orbit's semi-major axis.
Mathematically, it is given by the formula;
[tex] (\frac {T_{1}}{T_{2}})^2 = (\frac {r_{1}}{r_{2}})^3 [/tex]
Where;
T1 & T2 is the orbital period of a planetary object.
r1 & r2 is the mean distance of a planetary object.
Also, we know that the orbital period for earth, T1 = 365 days
Mean distance of earth = 1.49x10^8 km
Substituting into the equation, we have;
[tex] (\frac {365}{410})^2 = (\frac {1.49x10^{8}}{r_{2}})^3 [/tex]
[tex] (\frac {365}{410}})^2 = (\frac {1.49x10^{8}}{r_{2}})^3 [/tex]
[tex] (0.8902)^2 = (\frac {1.49x10^{8}}{r_{2}})^3 [/tex]
[tex] (0.7925) = (\frac {1.49x10^{8}}{r_{2}})^3 [/tex]
Cross-multiplying, we have;
[tex] (r_{2})^3 = \frac {1.49x10^{8}}{0.7925} [/tex]
Taking the cube root of both sides;
[tex] r_{2} = 1.61 * 10^8 km[/tex]
A 3.50-g bullet has a muzzle velocity of 250 m/s when fired by a rifle with a weight of 25.0 N. (a) Determine the recoil speed of the rifle. m/s (b) If a marksman with a weight of 650 N holds the rifle firmly against his shoulder, determine the recoil speed of the shooter and rifle.
Answer:
(a) 0.343 m/s
(b) 0.012 m/s
Explanation:
(a) From the question above,
MV = mv............................... Equation 1
Where M = mass of the rifle, V = recoiling speed of the rifle, m = mass of the bullet, v = velocity of the bullet.
make V the subject of the equation
V = mv/M........................... Equation 2
Given: m = 3.5 g = 0.0035 kg, v = 250 m/s, M = 25 N = 25/9.8 = 2.55 kg.
Substitute into equation 2
V = (0.0035×250)/2.55
V = 0.343 m/s.
(b) Similarly,
(M'+M)V' = mv....................... Equation 3
Where M' = mass of the marksman, V' = recoiling speed of the shooter and rifle
make V' the subject of the equation
V' = mv/(M'+M)................... Equation 4
Given: m = 3.5 g = 0.0035 kg, v = 250 m/s, M = 25 N = 25/9.8 = 2.55 kg, M' = 650 N = 650/9.8 = 66.33 N
Substitute into equation 4
V' = (0.0035×250)/(66.33+2.55)
V' = 0.8125/68.88
V' = 0.012 m/s
The recoil velocity can be obtained using the principle of conservation of linear momentum.
Using the principle of conservation of linear momentum;
momentum before collision = momentum after collision
Mass of the bullet = 3.50-g or 0.0035 Kg
Mass of the rifle = 2.5 Kg
Where;
M1 = mass of rifle
M2 = mass of bullet
u1 =initial velocity of rife
u2 = initial velocity of the bullet
(2.5 × 0) + (0.0035 × 250) = (0.0035 × 0) + (2.5 × v)
0.875 = 2.5 v
v = 0.35 m/s
For the shooter and the rifle;
(67.5 × 0) + (0.0035 × 250) = (0.0035 × 0) + (67.5 × v)
0.875 = 67.5 × v
v = 0.013 m/s
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When Coach Kwan notices that a player is getting tired, she takes out the tired player and substitutes a fresh player.
Which type of chemical reaction does this best model?
Answer:
is replacement
Explanation:
A small steel ball falls from rest through a distance of 3m. When calculating the time of fall, air resistance can be ignored because
Answer:
First, let's write the movement equations for this ball.
The only force acting on the ball will be the gravitational acceleration (because we ignore the air resistance) then the acceleration equation is:
a(t) = -9.8m/s^2
Where the minus sign is because the ball is falling down.
To get the velocity of the ball, we need to integrate over time to get:
v(t) = -(9.8m/s^2)*t + v0
Where v0 is the initial velocity of the ball. Because it falls from rest, we can conclude that the initial velocity is 0 m/s, then the velocity equation is:
v(t) = -(9.8m/s^2)*t
For the position equation we need to integrate again, here we get:
p(t) = -(1/2)*(9.8m/s^2)*t^2 + p0
Where p0 is the initial position. In this cse we know that the ball falls from a height of 3m, then po = 3m
The position equation is:
p(t) = -(1/2)*(9.8m/s^2)*t^2 + 3m
The ball will hit the ground when p(t) = 0m, then we need to solve the equation:
p(t) = -(1/2)*(9.8m/s^2)*t^2 + 3m = 0m
for t.
-(1/2)*(9.8m/s^2)*t^2 + 3m = 0m
3m = (1/2)*(9.8m/s^2)*t^2
3m*2 = (9.8m/s^2)*t^2
6m/(9.8m/s^2) = t^2
√(6m/(9.8m/s^2)) = t = 0.78s
The ball needs 0.78 seconds to hit the ground.
The correct answer is (d) the weight of steel ball is much larger than air resistance.
since the density of steel ball is quite higher than that of air. The weight of even a small steel ball will be much larger than the air resistance acting opposite to the motion of the steel ball. Hence in the case of a freely falling steel ball the air resistance can be neglected.
Learn more about air resistance:
https://brainly.com/question/2575108
A 845kg dragster (very fast car) accelerates from 2m/s to 30m/s in 0.9s. Determine the average force exerted on the dragster.
Plis I need help
Answer:
Explanation:
Just use the Force formula.
F = M . A
Acceleration Formula
A = V - Vo / Time
So...
F = 845 . (30 - 2 / 0.9)
F = 845 . 20
F = 16900 N
A small glass bead has been charged to 8.0 nC (nano-Coulombs). What is the magnitude of the electric field 2.0 m from the center of the bead
Given :
Charge on glass bead, Q = 8 nC .
To Find :
The magnitude of the electric field 2.0 m from the center of the bead.
Solution :
Electric field at position r is given by :
[tex]E = \dfrac{kQ}{r^2}\\\\E = \dfrac{9\times 10^9\times 8\times 10^{-9}}{2^2}\\\\E = 18\ N/C[/tex]
Therefore, the magnitude of the electric field 2.0 m from the center of the bead is 18 N/C .
Does the mass of an object make it need more force to move, and to stop?
Answer:
Yea
Explanation:
Let's compare a brick to a small table, does it take more force and strength to push a car or a small table? A car, because it's heavier and has more mass.
Answer:
Heavier objects (objects with more mass) are more difficult to move and stop. Heavier objects (greater mass) resist change more than lighter objects. Example: Pushing a bicycle or a Cadillac, or stopping them once moving. The more massive the object (more inertia) the harder it is to start or stop.
Explanation:
☝️
A soccer has been kicked as far as it can get with an initial momentum of 153 kg*m/s and the
ball weights 1.8 kg. What is the velocity of the ball?
Answer:
85 m/s
Explanation:
The formula for momentum is product of weight and velocity
p=mv where m is mass and v is velocity
Given that;
Momentum = 153 kg*m/s
Weight = 1.8 kg
Velocity = ?
p=mv
153 = 1.8 * v
153/1.8 = v
85 m/s
