Answer:
The answer is D (It reduced his average
force.)
PLEASE HELP ME WITH THIS
Answer:
Air masses tend to move from west to east.
1 ) when a ball is projected upwords its time of rising is ...............the time of falling .
a) greater than b) smaller than c) equal to d ) double
2 ) when an object falls freely under the effect of gravity , the distance moved is
a ) directly proportional to time
b ) inversely proportional to time
c ) directly proportional to square of time
d ) inversely proportional to square of time.
Answer:
correct answer is C
Explanation:
In this exercise, you are asked to complete the sentences so that the sentence makes sense.
1) in projectile launching, the only force that acts is gravity in the vertical direction, so the time of going up is EQUAL to the time of going down
correct answer C
2) when a body falls freely, the acceleration is the ratio of gravity, therefore if it starts from rest, its height is
y = v₀ t - ½ gt²
v₀ = 0
y = -1/2 g t²
so the position is not proportional to the square of the time
correct answer is C
A rocket sled accelerates from rest for a distance of 645 m at 16.0 m/s2. A parachute is then used to slow it down to a stop. If the parachute gives the sled an acceleration of -18.2 m/s2 and there is 500.0 m of sled track remaining after the shoot opens, will the sled stop before running off the track? Show why or why not?
Answer:
the stopping distance is greater than the free length of the track, the vehicle leaves the track before it can brake
Explanation:
This problem can be solved using the kinematics relations, let's start by finding the final velocity of the acceleration period
v² = v₀² + 2 a₁ x
indicate that the initial velocity is zero
v² = 2 a₁ x
let's calculate
v = [tex]\sqrt {2 \ 15.0 \ 645}[/tex]
v = 143.666 m / s
now for the second interval let's find the distance it takes to stop
v₂² = v² - 2 a₂ x₂
in this part the final velocity is zero (v₂ = 0)
0 = v² - 2 a₂ x₂
x₂ = v² / 2a₂
let's calculate
x₂ = [tex]\frac{ 143.666^2 }{2 \ 18.2}[/tex]
x₂ = 573 m
as the stopping distance is greater than the free length of the track, the vehicle leaves the track before it can brake
a violin is less than 0.5 m long. a bass fiddle is more than 1.5 m long. which instrument do you expect to be able to play notes with a lower pitch and why?
Explanation:
When there is a high frequency sound the speed of the vibrations is faster and makes a high pitch sound. When there is a low frequency sound the speed of the vibrations is slower and makes a lower pitch sound.
What is earth's magnetic field made of
Answer:
if you have a rotating electric current it will create a magnetic field on earth flowing of liquid metal in the outer core of the planets General Health recurrence the rotation of earth on its Axis causes this electric current to form a magnetic field which extends around the planet.
Explanation:. please give me brainlest
what is the power output needed from a motor to lift in the absence of friction a mass of 1.5 ×10⁴ kg 25 m in 6.0 s at constant speed
Answer:
the power output needed is 61.25 × 10⁴
Explanation:
The computation of the power output needed is shown below;
Given that
m = 1.5 ×10⁴ kg
v = 25m ÷ 6.0 s
And g = 9.8 m/sec^2
Now based on the above information
p = f × v
= mg × v
= 1.5 ×10⁴ × 9.8 × 25 ÷ 6
= 61.25 × 10⁴
Hence, the power output needed is 61.25 × 10⁴
explain the working and performance of a centrifugal clutch with a sketch
a centrifugal clutch works, as the name suggests, through centrifugal force. ... The rotation of the hub forces the shoes or flyweights outwards until they come into contact with the clutch drum, the friction material transmits the torque from the flyweights to the drum. The drive is then connected
The net force experienced by an object is increased. What affect does this have on the acceleration of the object?
Answer:
The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.
Explanation:
hope it helps pls give me brainless
What is one benefit to measuring your body’s flexibility?
A.
meeting the national requirement for flexibility
B.
determining your muscular strength
C.
tracking your flexibility improvements over time
D.
increasing the length of your life
Answer:
C
Explanation:
if you measure your body's flexibility then you can keep track of how flexible you have gotten over time
Prove the correctness of this equation s=vt + 1/2at
Answer:
The formula is dimensionally correct.
Explanation:
Given
[tex]s = ut + \frac{1}{2}at^2[/tex]
Required
Prove its correctness
Write out the dimension of each:
[tex]s = M^0LT^0[/tex] --- displacement
[tex]ut = M^0LT^{-1} * T[/tex] --- velocity * time
[tex]\frac{1}{2}at^2 = M^0LT^{-2} * T^2[/tex] --- acceleration * square of time
The expression becomes:
[tex]s = ut + \frac{1}{2}at^2[/tex]
[tex]M^0LT^0 = M^0LT^{-1} * T + M^0LT^{-2} * T^2[/tex]
Apply law of indices
[tex]M^0LT^0 = M^0LT^{-1+1} + M^0LT^{-2+2}[/tex]
[tex]M^0LT^0 = M^0LT^{0} + M^0LT^{0}[/tex]
[tex]M^0LT^0 = M^0LT^{0}[/tex]
Both sides of the equation are equal
a car is travelling at 18m/s accelerates ti 30m/s in 3seconds. what's the acceleration of the car
[tex] \Large {\underline { \sf {Required \; Solution :}}}[/tex]
We have ―
Initial velocity, u = 18 m/sFinal velocity, v = 30 m/sTime taken, t = 3 secondsWe've been asked to calculate acceleration.
[tex]\qquad \implies\boxed{\red{\sf{ a = \dfrac{v-u}{t} }}}\\[/tex]
a denotes accelerationv denotes final velocityu denotes initial velocityt denotes time[tex] \twoheadrightarrow \quad \sf {a = \dfrac{30-18}{3} \; ms^{-2} } \\ [/tex]
[tex] \twoheadrightarrow \quad \sf {a =\cancel{ \dfrac{12}{3} \; ms^{-2} }} \\ [/tex]
[tex]\twoheadrightarrow \quad \boxed{\red{\sf{ a = 4 \; ms^{-2} }}}\\[/tex]
Therefore, acceleration of the car is 4 m/s².
A small rubber wheel is used to drive a large pottery wheel. The two wheels are mounted so that their circular edges touch. The smalldrive-wheel has a radius of 2.20 cm and accelerates at the rate of 8.00 rad/s2, and it is in contact with the pottery wheel (radius 28.0 cm). Both wheels move without slipping.The rubber drive wheel rotates in the clockwise sense.
Required:
a. Find the angular acceleration (both magnitude and direction) of the large pottery wheel.
b. Calculate the tune it takes the pottery wheel to reach its required speed of 60 rpm. if both wheels start from rest.
Answer:
[tex]0.629\ \text{rad/s}^2[/tex] counterclockwise
[tex]9.98\ \text{s}[/tex]
Explanation:
[tex]r_1[/tex] = Small drive wheel radius = 2.2 cm
[tex]\alpha_1[/tex] = Angular acceleration of the small drive wheel = [tex]8\ \text{rad/s}^2[/tex]
[tex]r_2[/tex] = Radius of pottery wheel = 28 cm
[tex]\alpha_2[/tex] = Angular acceleration of pottery wheel
As the linear acceleration of the system is conserved we have
[tex]r_1\alpha_1=r_2\alpha_2\\\Rightarrow \alpha_2=\dfrac{r_1\alpha_1}{r_2}\\\Rightarrow \alpha_2=\dfrac{2.2\times 8}{28}\\\Rightarrow \alpha_2=0.629\ \text{rad/s}^2[/tex]
The angular acceleration of the pottery wheel is [tex]0.629\ \text{rad/s}^2[/tex].
The rubber drive wheel is rotating in clockwise direction so the pottery wheel will rotate counterclockwise.
[tex]\omega_i[/tex] = Initial angular velocity = 0
[tex]\omega_f[/tex] = Final angular velocity = [tex]60\ \text{rpm}\times \dfrac{2\pi}{60}=6.28\ \text{rad/s}[/tex]
t = Time taken
From the kinematic equations of linear motion we have
[tex]\omega_f=\omega_i+\alpha_2t\\\Rightarrow t=\dfrac{\omega_f-\omega_i}{\alpha_2}\\\Rightarrow t=\dfrac{6.28-0}{0.629}\\\Rightarrow t=9.98\ \text{s}[/tex]
The time it takes the pottery wheel to reach the required speed is [tex]9.98\ \text{s}[/tex]
Which of the following is true about scientific knowledge?
OA. It can be changed as new information becomes available.
OB. It cannot be changed under any circumstances.
OC. It can be changed only if all scientists approve the change.
OD. It can be changed without information that supports the change.
The true statement about scientific knowledge is it can be changed as new information becomes available.
option A
What is scientific knowledge?Science is a dynamic process, and scientific knowledge is continually evolving as new data and evidence are discovered.
Scientific theories and hypotheses are constantly being tested and refined, and they can be modified or even rejected if new evidence contradicts them.
This is one of the key features of the scientific method - that it is self-correcting and always open to revision based on new evidence.
Thus, the true statement about scientific knowledge is it can be changed as new information becomes available.
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advice students on how to manage stress throughout their studies
Answer:
Drink water
Make your find fresh by doing the stuff you love too ❤️
Two resistors 5 ohm's each can be combined to give an equivalent resistance of
Answer: 10 Ω or 2.5 Ω
Explanation:
In series resistance R = 5 Ω + 5 Ω =10 Ω. If resistors are parallel, resistance is
1/R = 1/5Ω+ 1/5Ω and R = 2,5 Ω
Which of the following is a true statement for a child's toy spinning in a circle at constant speed?
a) The speed is constant, the velocity is constant, and the angular velocity is constant. b) The speed is constant, the velocity is not constant, and the angular velocity is constant. c) The speed is constant, the velocity is not constant, and the angular velocity is not constant. d) The speed is constant, the velocity is constant, and the angular velocity is not constant.
explain your answer.
Answer:
B
Explanation:
I am pretty sure it is B as the speed is obviously constant but the velocity is not constant as it defines as the rate of speed AND DIRECTION meaning that it is not constant as it always changes direction. And angular velocity is constant.
A piano tuner stretches a steel piano wire with a tension of 765 N. The steel wire has a length of 0.800 m and a mass of 6.00 g . What is the frequency f1 of the string's fundamental mode of vibration
Answer:
the frequency of the fundamental mode of vibration is 199.6 Hz
Explanation:
Given;
tension of the piano wire, T = 765 N
length of the steel wire, L = 0.8 m
mass of the steel wire, m = 6.00 g = 6 x 10⁻³ kg
The frequency of the fundamental mode of vibration is calculated as;
[tex]f_o = \frac{1}{2l} \sqrt{\frac{T}{\mu} }[/tex]
where;
μ is the mass per unit length [tex]= \frac{6.0 \times 10^{-3}}{0.8} = 7.5 \times 10^{-3} \ kg/m[/tex]
[tex]f_o = \frac{1}{2l} \sqrt{\frac{T}{\mu} } \\\\f_o = \frac{1}{2\times 0.8} \sqrt{\frac{765}{7.5 \times 10^{-3}} } \\\\f_o = 199.6 \ Hz[/tex]
Therefore, the frequency of the fundamental mode of vibration is 199.6 Hz
WHEN AN OBJECT IS DROPPED WHAT HAPPENDS TO THE POTENTIAL AND KENETIC ENERGY AS IT FALLS?
Answer:
The sum of an object's potential and kinetic energies is called the object's mechanical energy. As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy.
Explanation:
Answer:
the potential decrease and kinetic increase
Explanation:
because it goes from a state of rest to a state of movement
Can someone pls help! I’m stuck on c and d. I’ll rate your answer the brainliest
Answer:
i think is c
Explanation:
Answer:
C
Explanation:
C makes more sense than D, Because it says the minimum value is when it stays at rest.
A closed, rigid container holding 0.2 moles of a monatomic ideal gas is placed over a Bunsen burner and heated slowly, starting at a temperature of 300 K. The initial pressure of the ideal gas is atmospheric pressure, and the final pressure is four times the initial pressure.
Determine the following:
a. the change in the internal energy of the gas.
b. the work done by the gas.
c. the heat flow into or out of the gas.
Answer:
a) 2250 J
b) 0 J
c) 2250 J
Explanation:
a) Since, the process is isochoric
the change in internal energy
[tex]\Delta U = n C_v(T_f-T_i)[/tex]
Here, n = 0.2 moles
Cv = 12.5 J/mole.K
We have to find T_f so we can use gas equation as
[tex]\frac{P_1V_1}{P_2V_2} =\frac{T_i}{T_f}\\Since, V_1=V_2 [isochoric/process]\\\Rightarrow \frac{P_{atm}}{4P_{atm}} = \frac{300}{T_f} \\\Rightarrow T_f = 1200 K[/tex]
So, [tex]\Delta U= 0.2\times12.5(1200-300)\\=2250 J[/tex]
b) Since, the process is isochoric no work shall be done.
c) By first law of thermodynamics we have
[tex]\Delta U = Q-W\\Since, W = 0\\\Delta U = Q\\Therefore, Q = 2250 J[/tex]
Since, Q is positive 2250 J of heat will flow into the system.
What is R2 in the circuit?
WILL GIVE BRAINLIEST !!!!
Answer:
1. Rₑq = 4 Ω
2. R₂ = 6 Ω
3. Vₜ = 12 V, V₁ = 12 V, V₂ = 12 V
4. Iₜ = 3 A, I₁ = 1 A, I₂ = 2 A
Explanation:
1. Determination of the equivalent resistance
Voltage (V) = 12 V
Current (I) = 3 A
Resistance (Rₑq) =?
V= IRₑq
12 = 3 × Rₑq
Divide both side by 3
Rₑq = 12 / 3
Rₑq = 4 Ω
Thus, the equivalent resistance (Rₑq) = 4 Ω
2. Determination of R₂.
Equivalent resistance (Rₑq) = 4 Ω
Resistance 1 (R₁) = 12 Ω
Resistance 2 (R₂)
Since the resistor are in parallel arrangement, the value of R₂ can be obtained as follow:
Rₑq = R₁ × R₂ / R₁ + R₂
4 = 12 × R₂ / 12 + R₂
Cross multiply
4(12 + R₂) = 12R₂
48 + 4R₂ = 12R₂
Collect like terms
48 = 12R₂ – 4R₂
48 = 8R₂
Divide both side by 8
R₂ = 48 / 8
R₂ = 6 Ω
3. Determination of the total voltage (Vₜ), V₁ and V₂.
From the question given above, the total voltage is 12 V
Since the resistors are arranged in parallel connection, the same voltage will go through them.
Thus,
Vₜ = V₁ = V₂ = 12 V
4. Determination of the total current (Iₜ), I₁ and I₂
From the question given above, the total current (Iₜ) is 3 A
Next, we shall determine I₁. Since the resistors are arranged in parallel connection, different current will pass through each resistor respective.
Vₜ = V₁ = 12 V
R₁ = 12 Ω
I₁ =?
V₁ = I₁R₁
12 = I₁ ×12
Divide both side by 12
I₁ = 12 / 12
I₁ = 1 A
Next, we shall determine I₂. This can be obtained as follow:
Iₜ = 3 A
I₁ = 1 A
I₂ =?
Iₜ = I₁ + I₂
3 = 1 + I₂
Collect like terms
I₂ = 3 – 1
I₂ = 2 A
I really need the answer
Answer:
The first answer is correct. All of the other options include sound, which travels by material force, and can not be transmitted in a vacuum. Infra-red, radio, and microwaves are all different frequencies of light, and can thus travel through a vacuum.
a pool and stops at the
Which best describes his
motion?
A. Linear
B. Projectile
C. Vibrational
In Linear motion the swimmer swims
Answer: A
Explanation: Linear motion.
A barometer reads 780 mm Hg. Mercury has a density of 1.36 x 10^4 kg /m^3.
What is the pressure of the atmosphere in N / m^2?
A 1.1 x 10^4 N/m^2
B 1.1 x 10^5 N/m^2
C 1.1 x 10^7 N/m^2
D 1.1 x 10^8 N/m^2
How do we get to the answer? According to the mark scheme, it's B.
Answer:
B
Explanation:
Pressure = density × g × height
[tex]p \: = (1.36 \times {10}^{4} )(10)(780 \times {10}^{ - 3} ) \\ p = 1.1 \times {10}^{5} [/tex]
The pressure of the atmosphere, when a barometer reads 780 mm Hg. Mercury which a density of 1.36 x 10^4 kg /m^3 is B 1.1 x 10^5 N/m^2
This problem can be solved using the formula below
P = dgh................. Equation 1
Where P = Pressure of the atmosphere, d = density of the mercury, h = height of the mercury, g = acceleration due to gravity.
From the question,
Given: d = 1.36×10⁴ kg/m³, h = 780 mm = 0.78 m,
Constant: g = 10 m/s²
Substitute these values into equation 1
P = (1.36×10⁴)(10)(0.78)
P = 10.608×10⁴ N/m²
P ≈ 1.1×10⁵ N/m²
Hence the right answer is B. 1.1×10⁵ N/m²
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1. A 455 g mass, hanging at rest on a spring, stretches the spring 22.4 cm beyond its relaxed
position. What is the spring constant of that spring?
Answer:
19.9 N/m
Explanation:
From the question,
Applying Hook's law
F = Ke.................. Equation 1
Where F = Force on the spring, k = spring constant, e = extension
But the force on the spring is the weight of the mass
Therefore,
mg = ke.................. Equation 2
Where m = mass. g = acceleration due to gravity
make e the subject of the equation
e = mg/e................ Equation 3
Given: m = 455 g = 0.455 kg, e = 22.4 cm = 0.224 m,
Constant: g = 9.8 m/s²
Substitute these values into equation 3
e = (0.455×9.8)/0.224
e = 19.9 N/m
The spring constant of the given spring is 20 N/m.
The given parameters:
Mass attached, m = 455 g = 0.455 kgExtension of the spring, x = 22.4 cm = 0.224 mThe spring constant is calculated by applying Hooke's law as follows;
[tex]F = kx\\\\mg = kx\\\\k = \frac{mg}{x} \\\\k = \frac{0.455 \times 9.8}{0.224} \\\\k = 20 \ N/m[/tex]
Thus, the spring constant of the spring is 20 N/m.
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2. Oscar walked to the milktea house for a snacks. He walk 2 kilometers
east, 2 kilometers south, and 2 kilometers west. What distance did he
cover? What was the displacement?
The distance Oscar covered was 6km while the displacement was 2km.
What is Displacement?Displacement is defined as the vector whose length is the shortest
distance from the initial to the final position of a point M.
Distance = Total length of space between points
= 2km+ 2km+ 2km = 6km.
Displacement = 2km.
This is because it is the shortest distance from the positions in this
scenario.
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In one cycle of any heat engine
A. the net work done is larger than the heat exhausted.
B. more heat flows from the engine than enters the engine.
C. The internal energy of the engine does not change.
D. the net heat flow is zero.
Answer:
D. the net heat flow is zero
Explanation:
In one cycle of any heat engine, three things happen:
Heat is added; this causes high temperature in the engine ([tex]Q_H[/tex])Some of the energy from that input heat is used to perform work (W). The rest of the heat is removed at a relatively cold temperature ([tex]Q_C[/tex]).[tex]Q_H = W + Q_C[/tex]
Conclusively, the net heat flow is zero
A magnetic field is passing through a loop of wire whose area is 0.014 m^2. The direction of the magnetic field is parallel to the normal to the loop, and the magnitude of the field is increasing at the rate of 0.19 T/s.
a. Determine the magnitude of the emf induced in the loop.
b. Suppose the area of the loop can be enlarged or shrunk. If the magnetic field is increasing as in part (a), at what rate (in m^2/s) should the area be changed at the instant when B = 1.6 T if the induced emf is to be zero? (Give the magnitude of the rate of change of the area.) (m^2/s). Explain whether the area is to be enlarged or shrunk.
Answer:
a. 0.00266v
b. -0.0016625
the area should be shrunk
Explanation:
the magnitude of the EMF induced in the loop
= area * rate
= 0.014 * 0.19
= 0.00266 V
B we are to solve for the rate at which the are has to be change with B = 1.6
δA/δt = -A/B * dB/dt
= (-0.014 * 0.19) /1.6
= -0.0016625
the sign is negative so the EMT is negative and so the area has to be shrunk.
Definition of continental polar
cold, dry, and stable air masses .
How do particle motion and temperature change as a material absorbs heat?