Answer:
(a)3.09 m/sec (b)θ= 35.28° (c) t =3.43 sec
Explanation:
Solution
Given that:
The swimming speed of swimmer =5.35 m/s
The downstream angle = 30°
Now,
(a)we find speed of the current which is given below:
V = V swimmer + V river
Tan 30° = Vr/Vs
Thus
Vr = 5.35 * tan 30°
Vr = 5.35 * 0.5773
= 3.09 m/sec
(b)She would have velocity at direction such that she reaches across the shore
Then
Vs sin θ =Vr
sin θ = Vs/Vr
sin θ = 3.09/5.35
θ= 35.28°
Therefore, She had to make θ= 35.28° on another side of the river
(c) Thus
t = d/Vs cosθ
=15/5.35 * cos (35.28°)
t =3.43 sec
A baboon steals an apple and runs to a nearby boulder 10.0\,\text m10.0m10, point, 0, start text, m, end text to its left. The baboon reaches the boulder in 1.0\,\text s1.0s1, point, 0, start text, s, end text with a constant acceleration of 20.0\,\dfrac{\text m}{\text s^2}20.0 s 2 m 20, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, squared, end fraction leftward. What was the baboon's initial velocity when it started running to the boulder?
Given that,
Distance = 10 m
Time = 1.0 sec
Acceleration a =20 m/s²
We need to calculate the baboon's initial velocity
Using equation of motion
[tex]s=ut+\dfrac{1}{2}at^2[/tex]
Where, s = distance
t = time
a = acceleration
Put the value in to the formula
[tex]10=u\times1+\dfrac{1}{2}\times20\times1^2[/tex]
[tex]u=10-10[/tex]
[tex]u=0\ m/s[/tex]
Hence, The baboon's initial velocity is zero.
A car company is performing brake tests on one of its cars. The car reaches a speed of 160 km/h and then hits the brakes to slow down at a rate of 11.0 m/s2 . A) How long does it take for the car to stop b) How far does the car travel when braking? A rate of 11.0 m/s2 .
Answer:
a) t = 4.04 s , b) x = 89.77 m
Explanation:
This is a one-dimensional kinematics exercise.
a) Let's use caution to find the time, the vehicle speed when stopped is zero
v = v₀ - at
let's reduce the magnitudes to the SI system
v₀ = 160 km /h (1000m / 1km) (1h / 3600s) = 44.44 m / s
0 = v₀ - at
t = v₀ / a
t = 44.44 / 11
t = 4.04 s
b) to calculate the distance traveled we use
x = v₀t - ½ a t²
x = 44.44 4.04 - ½ 11.0 4.04²
x = 179.54 - 89.77
x = 89.77 m
A car starts from rest, then accelerates at 1.20 m/s^2 for 7.00 s. It hits the brakes, slowing to stop at a rate of -4.25 m/s^2. What is the total time for the problem? (Unit = s) PLEASE HELP!!
Answer:
8.98 secsExplanation:
First part of the journey;
If the car starts from rest, then accelerates at 1.20 m/s^2 for 7.00 s, the total time taken during this period is 7.0s.
But then lets get the velocity v of the car during its first part of the journey.
Using the formula v1 = u1+ at1
v = 0+1.2(7)
v = 8.4m/s
Second part of the journey is when the driver hits the brake and slowing to stop at a rate of -4.25 m/s^2. To calculate the time it takes by the body to decelerates, we will use the equation of motion v2 = u2 + at2
v = final velocity of the car during the second part of the journey
u = initial velocity of the car during the second part of the journey
a = deceleration
t = time taken
Given v2 = 0m/s, u2 = 8.4m/s, a = -4.25m/s²
0 = 8.4-4.25t2
4.25t2 = 8.4
t2 = 8.4/4.25
t2 = 1.98secs
Total time taken for the journey = t1+t2
= 7.0s + 1.98s
= 8.98secs
How is mercury barometer constructed ?
Answer:
A mercury barometer is a device use to measure stomspheric pressure and is constructed as following:
A mercury barometer requires a tube which has one close end, and one open end.Tube is placed upside down in a beaker in such a way so that one end open in the beaker and the other remain outside of the beaker. The barometric liquid (mercury) is then filled in the tube by pouring mercury liquid in the beaker.The position of tube creates vacuum between the closed end of the tube and liquid surface and the Mercury has high density that is why used as the liquid to measure pressure.
In this graph, what is the displacement of the particle in the last teo seconds?
A. 0.2 meters
B. 2 meters
C. 4 meters
D. 6 meters
Answer: B
Explanation:
Displacement is a vector quantity. it is the distance covered in a specific direction.
Whereas, Velocity = displacement/time
Make displacement the subject of formula
Displacement = velocity × time
From the graph, velocity is constant which is equal to 1 m/s
Displacement in the last two seconds will be velocity multiply by 2. Since time = 2s. Therefore,
Displacement = 1 × 2 = 2 m
So, the particle displacement in the last two seconds will be 2 metres
If It took 40 Seconds for a vehicle of weight 40,000 Newton to move round a 7 metres, What time will it achieve same feat for another circular path Of radius 21 metres given the Condition of the vehicle remains the same.
Answer:
t = 376.99 s
Explanation:
We must solve this problem with the equations and kinematics, let's start by looking for the speed of the vehicle,
v = d / t
v = 7/40
v = 0.175 m / s
Since the speed e remains constant, we must find the length of the circle is
L = 2π r
L = 2π 21
L = 131.95 m
In the problem it does not specify clearly, but in general the curves of the road correspond to half a circle, so the length of the road is
L ’= L / 2
L ’= 131.95 / 2 = 65.97 m
as the speed is constant
t = L ’/ v
t = 65.97 / 0.175
t = 376.99 s
How far away from the surface of earth does the acceleration due to gravity will be inclined by 36% of its value on the surface of earth? Radius of earth is 6400 km
Answer:
1,600 km
Explanation:
since the acceleration due to gravity reduces by 36%, it means that (1 - 36%) of acceleration still remains:
g' = 64g/100
using the acceleration formula:
g' = g x [R² / (R + height)²]
64g/100 = g x [R² / (R + height)²]
64/100 = R² / (R + height)²
√(64/100) = √[R² / (R + height)²]
8/10 = R / (R + height)
8 (R + height) = 10R
8R + 8height = 10R
8height = 2R
height = 2R / 8 = R / 4
R = 6,400 km
height = 6,400 km / 4 = 1,600 km
Answer:
The acceleration due to gravity will be inclined 1600 KM by 36% of its value on the surface of earthHoliday lights are often connected in series and use special lamps that short out when the potential difference across a lamp increases to the line voltage. Generate an explanation why and explain why these light sets might blow their fuses after many bulbs have failed.
Answer:
If there isn't this type of mechanism, the whole setup will blow even if only one lamp burns out. Doing this mechanism is to decrease the overall resistance resulting in an increased current (Since resistance and current are inversely related) which is the best to blast the fuse.
1. How much heat energy is required to raise the temperature of a 5 kg aluminium bar
from 28°C to 68°C ?
( Specific heat capacity of aluminium = 900 J kg C)
Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
. What happens to the polarity of an electromagnet when the direction of the current passing through it is reversed?
Answer:
The polarity of electromagnet also gets reversed when the direction of current is reversed. The current flows from negative terminal to positive terminal in an electromagnet due to the flow of electrons so polarity is also established in the electromagnet. As, the current direction is reversed, the polarity of magnet also gets reversed because the polarity of magnet depends on the direction of the current.
A 0.3-m-radius automobile tire rotates how many revolutions after starting from rest and accelerating at a constant 2.13 rad/s2 over a 23.2-s interval?
Answer:
The automobile tire rotates 91 revolutions
Explanation:
Given;
angular acceleration of the automobile, α = 2.13 rad/s²
time interval, t = 23.2-s
To calculate the number of revolutions, we apply the first kinematic equation;
[tex]\theta = \omega_i \ + \frac{1}{2} \alpha t^2[/tex]
the initial angular velocity is zero,
[tex]\theta =0\ + \frac{1}{2} (2.13) (23.2)^2\\\\\theta = 573.2256 \ Rad[/tex]
Find how many revolutions that are in 573.2256 Rad
[tex]N = \frac{\theta}{2 \pi} = \frac{573.2256}{2\pi} \\\\N = 91 \ revolutions[/tex]
Therefore, the automobile tire rotates 91 revolutions
Find total displacement. 10 points. Will give brainliest!
Answer:
20.5 m North East.
Explanation:
The attached photo gives the illustration of Alan's walk.
In the attached photo, d is the total displacement of Alan's walk.
Thus, we can obtain the value of by using the cosine rule as shown:
Angle D = 138°
Side opposite D = d
Side opposite C = 12 m
Side opposite E = 10 m
d² = c² + e² – 2ce Cos D
d² = 12² + 10² – 2 × 12 × 10 × Cos 138°
d² = 144 + 100 – 240 × Cos 138°
d² = 244 – – 178.355
d² = 244 + 178.355
d² = 422.355
Take the square root of both side
d = √422.355
d = 20.5 m.
Since his new position is on a bearing of 042°, Alan' total displacement is 20.5 m North East.
HURRY!!!!
Fred and Ted are racing cars down a frictionless track with a jump at the bottom
when suddenly an argument breaks out. Fred says, “If we release the cars from a
point twice as high as we are currently doing so, the cars will have twice the
gravitational potential energy, and therefore be travelling twice fast when they hit
the jump." Ted says, “In order to double the speed of the cars when they hit the
ramp, I think we will have to more than double the height!" Who is right? Prove it!
Answer:
Ted is correct
Explanation:
The equation for gravitational potential energy is PE = m·g·h
The equation for gravitational kinetic energy is KE = 1/2·m·v²
Where:
m = Mass of the object (The racing car)
g = Acceleration due to gravity
h = The height to which the object is raised
v = Velocity of motion of the object
From the principle of conservation of energy, energy can neither be created nor destroyed but changes from one form to another, we have;
Potential energy gained from location at height h = Kinetic energy gained as the object moves down the level ground
m·g·h = 1/2·m·v² canceling like terms gives
g·h = 1/2·v²
v = (√2·g·h)
If the speed is doubled, we have
2·v = 2× (√2·g·h) = (√2·g·4·h)
Therefore, if 2·v = v₂ then v₂ = (√2·g·4·h)
Since g, the acceleration due to gravity, is constant, it means that the initial height must be multiplied or increased 4 times to get the new height, that is we have;
v₂ = (√2·g·4·h) = (√2·g·h₂)
Where:
4·h = h₂
Which gives;
v₂² = 2·g·h₂
1/2·v₂² = g·h₂
1/2·m·v₂² = m·g·h₂ Just like in the first relation
Therefore, Ted is correct s they need to go up four times the initial height to double the speed.
Identify one simple machine used at your home and explain how it makes your work easier
Answer:
they are,
1. scissor = they are very useful for cutting papers, clothes, etc. if there wouldn't be sicssor than we would not be able to cut various things . it has made easier to cut tgings.
2. nailcutter= it is also one type of simple machine. it is used to trim our nails. if there would be no nailcutter then our nail would be so dirty and long.
hope it helps..
Newton’s third law of motion says that for every action there is a(n) and opposite reaction.
Answer:
for every action thete is an equal and opposite reaction
Answer:
Newton’s third law of motion says that for every action there is a(n)
equal and opposite reaction.
Explanation:
just got it right edg 1928
What does the use of the phrase "the lucky ones"
convey about the author's viewpoint?
What does the phrase "But we never ate enough to
satisfy our hunger" demonstrate about the author?
Answer:
1. He feels worse off.
2. His awareness of the grim situation.
Explanation:
Elie Weisel's memoir "Night" is about the persecution of the jews by the Germans during the worst genocide in world history. The events leading up to the Holocaust and the resulting after-effects through his personal experience provides one of the most prominent witness accounts of the crime.
When Weisel states that "lying down wasn't an option", he reveals how congested space was in the cabin. The "lucky ones" were able to breathe in the fresh air from the window, while the rest have to be satisfied with wherever they are. This reveals his realization of the grim situation inside the over-packed cabin, where there is hardly any space to move.
And when he said that they "never ate enough to satisfy our hunger", he presents the realization and understanding of the grim situation in the train's cabin where eating is not a luxury, but a necessity to stay alive. And for that, they know they have to "economize, to save for tomorrow" rather than just stay full once.
Answer:
1. He feels worse off.
2. His awareness of the grim situation.
Explanation:
if spiderman runs and jumps horizontally from the top of a 200m high building, what does he need his velocity to be to land on a building 100m high, 10m away from him?
Answer:
v = 2.22 m/s
Explanation:
First we apply the second equation of motion to the vertical motion of the body:
s = Vi t + (1/2)gt²
where,
s = y = vertical distance covered = 200 m - 100 m = 100 m
Vi = V₀y = Vertical Component of Initial Velocity = 0 m/s (because spider man jumps horizontally, thus his velocity has no vertical component initially)
t = Time Taken to Land on 100 m high building = ?
g = 9.8 m/s²
Therefore,
100 m = (0 m/s)t + (0.5)(9.8 m/s²)t²
t² = (100 m)/(4.9 m/s²)
t = √(20.4 s²)
t = 4.5 s
Now, we analyze the horizontal motion. Neglecting air friction, the horizontal motion is uniform with uniform velocity. Therefore,
s = vt
where,
s = x = horizontal distance covered = 10 m
v = V₀ₓ = Horizontal Component of Initial Velocity = Initial Velocity = ?
Therefore,
10 m = v(4.5 s)
v = 10 m/4.5 s
v = 2.22 m/s
I NEED HELP PLEASE, THANKS! :)
Generate an explanation for the following formula: P = I²R . Explain.
Answer:
P = VI = (IR)I = I2R
Explanation:
What the equation means is that if you double the current you end up with 4 times the power loss. It's like the area of carpet you need for a room - if you make the room twice as long and twice as wide you need 4x as much carpet. The physical explanation is that the voltage difference along a wire depends on the current - more current flowing with a resistance means more voltage (pressure of electricity if you like) is built up.
This extra voltage means more power. So if you double the current your would double the power, but you also double the voltage which doubles the power again = 4x as much power. P = VI = (IR)I = I2R
I hope this helps you out, if I'm wrong, just tell me.
As I mentioned earlier, Ohm's law gives us the formula P = IV, where V is the voltage ( also known as the electrical potential difference ) and I is the current. It is confusing that P = I²R and P = IV are one in the same - so I want to go a bit deeper on that.
We have three formulas, P = IV, P = I²R, and P = V² / R. Each are considered the same. The two formulas P = I²R, and P = V² / R are derived from the statement that P = IV, under the condition V = IR. Substitute the value of V from this second condition V = IR into P = IV. You would get the following -
P = I( IR ),
P = I²R
That is how one can derive the formula P = I²R, and how P = IV and P = I²R are thought to be one in the same. If you would like, take a look at how to get the formula " P = V² / R, "
V = IR, P = IV
I = V / R, P = IV
P = ( V / R )V,
P = V² / R
Hope that helps!
A man can walk three blocks east and four blocks north in 20 min. He can drive 12 times that distance in the same amount of time. How far can the man
drive in 20 min? Assume that each block is 0.3 kilometers.
Answer: 25.2 km
Explanation:
3 blocks east and four blocks east = 7 blocks
1 block = 0.3 km --> 7 blocks = 2.1 km
12 times 2.1 km = 25.2 km
A runner starts from rest and speeds up with constant acceleration. If she
has gone a distance of 30 m at the point when she reaches a speed of 8 m/s,
what is her acceleration?
A. 7.5 m/s2
B. 3.8 m/s2
C. 9.1 m/s2
D. 1.1 m/s2
Answer:
a = 1.07 m/s^2
Explanation:
The computation of the acceleration is shown below:
As we know that
[tex]v_f^{2} - v_i^{2} = 2 ad[/tex]
where,
v_i = 0 m/s = initial speed
v f = 8 m/s = final speed
d = 30m = distance
Now placing these values to the above equation
[tex]8^{2} - 0 = 2 \times a \times 30[/tex]
64 = 60a
a = 1.07 m/s^2
We simply applied the above formula so that we could able to determine the acceleration
The table shows data for the planet Uranus. A 2 column table with 4 rows. The first column is labeled Quantity with entries, Escape velocity in kilometers per second, Gravitational acceleration in meters per second squared, Orbital velocity in kilometers per second, Length of day in hours. The second column is labeled Value with entries, 21.3, 8.7, 6.8, 17.2. To the nearest whole number, how much would a 25.0 kg rock weigh on Uranus?To the nearest whole number, how much would a 25.0 kg rock weigh on Uranus?
Answer:
218 N
Explanation:
edge2020
The table shows data for the planet Uranus, the weight of a 25.0 kg rock on Uranus would be approximately 218 N.
In physics, weight refers to the force imposed on an item owing to gravity. It is the gravitational force exerted on the mass of an item.
The gravitational acceleration value supplied in the table may be used to calculate the weight of a 25.0 kilogramme rock on Uranus.
Uranus' gravitational acceleration is given at 8.7 metres per second squared.
The weight of an object is derived by multiplying its mass (m) by its gravitational acceleration (g):
Weight = mass * gravitational acceleration
Weight = 25.0 kg * 8.7 m/s^2
Weight = 217.5 N
The weight of a 25.0 kg rock on Uranus would be approximately 218 N.
For more details regarding weight, visit:
https://brainly.com/question/31993417
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If it takes 600 N to move a box 5 meters, how much work is done on the box?
O
A. 600 J
OB. 5,000 J
O C. 3,000 J
O D. 120 J
Answer:
3000 JOption C is the correct option.
Explanation:
Given,
Force = 600 N
Distance = 5 meters
Work = ?
Now,
Work = Force [tex] \times [/tex] distance
[tex] = 600 \times 5[/tex]
Calculate the product
[tex] = 3000 \: [/tex] Joule
Hope this helps...
Good luck on your assignment..
Determine the amount of time for polonium-210 to decay to one fourth its original quantity. The half-life of polonium-210 is 138 days. Explain.
Answer:
276 days
Explanation:
1/4 th of the original means 2 half lives
1 half life = 138 days
So,
2 half lives = 276 days
A car travels 500m in 50s, then 1,500m in 75s. Calculate its averages speed for the whole journey
Answer:
15m/s
Explanation:
500 ÷ 50 = 10m/s
1500 ÷ 75 = 20m/s
10 + 20 = 30
30 ÷ 2 = 15m/s
Answer: 16 miles per second
Explanation:
Find the total distance traveled and the total time.
[tex]\text{average rate}=\dfrac{1500+500}{75+50}=\dfrac{2000\ miles}{125\ second}=\large\boxed{16\ mps}[/tex]
Q- A body is acted upon by two forces 30N due east and 40N due North. Calculate
resultant and its direction.
Answer:
the following image will make you understand
Explanation:
A hydrogen bond is a special form of a(n)
a. covalent bond.
b. dipole-dipole force.
C. ionic bond.
d. London dispersion force.
Answer:
B
Explanation:
N2 + O2 → 2NO N-N triple bond: 941 kJ/mol O-O double bond: 495 kJ/mol N-O bond: 201 kJ/mol
Answer:
[tex]\large \boxed{\text{761 kJ}}[/tex]
Explanation:
You calculate the energy required to break all the bonds in the reactants.
Then you subtract the energy needed to break all the bonds in the products.
N₂ + O₂ ⟶ 2NO
N≡N + O=O ⟶ 2O-N=O
Bonds: 2N≡N 1O=O 2N-O + 2N=O
D/kJ·mol⁻¹: 941 495 201 607
[tex]\begin{array}{rcl}\Delta H & = & \sum{D_{\text{reactants}}} - \sum{D_{\text{products}}}\\& = & 2 \times 941 +1 \times 495 - (2 \times 201 + 2\times 607)\\&=& 2377 - 1616\\&=&\textbf{761 kJ}\\\end{array}\\\text{The enthalpy of reaction is $\large \boxed{\textbf{761 kJ}}$}.[/tex]
The count rate of a radioactive source decreases from 1600 counts per minute to 400 counts per minute in 12 hours. What is the half-life of the source?
Answer:
[tex]t_{1/2}=6 h[/tex]
Explanation:
Let's use the decay equation.
[tex]A=A_{0}e^{-\lambda t}[/tex]
Where:
A is the activity at t timeA₀ is the initial activityλ is the decay constantWe know that [tex]\lambda=\frac{ln(2)}{t_{1/2}}[/tex]
So we have:
[tex]\lambda=\frac{ln(A/A_{0})}{t}[/tex]
[tex]\frac{ln(2)}{t_{1/2}}=\frac{ln(A/A_{0})}{t}[/tex]
[tex]t_{1/2}=\frac{t*ln(2)}{ln(A/A_{0})}[/tex]
[tex]t_{1/2}=6 h[/tex]
Therefore, the half-life of the source is 6 hours.
I hope it helps you!
Plzz answer this questions
will mark as brainlist
Answer:
1. 19.28 secs
2. 154.22 m
Explanation:
The following data were obtained from the question:
Initial velocity (u) = 16 m/s
Final velocity (v) = 0
Force (F) = 1000 N
Mass (m) = 1200 Kg
Time (t) =..?
Distance (s) =...?
Next, we shall determine the acceleration of the car. This can be obtained as follow:
Force (F) = 1000 N
Mass (m) = 1200 Kg
Acceleration (a) =.?
Force (F) = mass (m) x acceleration (a)
F = ma
1000 = 1200 x a
Divide both side by 1200
a = 1000/1200
a = 0.83 m/s²
Since the car is coming to rest, it means it is decelerating. Therefore, the acceleration is – 0.83 m/s²
1. Determination of time taken for the car to halt i.e stop. This can be obtained as follow:
Initial velocity (u) = 16 m/s
Final velocity (v) = 0
acceleration (a) = – 0.83 m/s²
Time (t) =.?
v = u + at
0 = 16 + (–0.83 x t)
0 = 16 – 0.83t
Rearrange
0.83t = 16
Divide both side by 0.83
t = 16/0.83
t = 19.28 secs.
Therefore, the time taken for the car to halt is 19.28 secs.
2. Determination of the distance travelled by the car before coming to rest. This can be obtained as follow:
Initial velocity (u) = 16 m/s
Final velocity (v) = 0
acceleration (a) = – 0.83 m/s²
Distance (s) =..?
v² = u² + 2as
0 = 16² + (2 x –0.83 x s)
0 = 256 – 1.66s
Rearrange
1.66s = 256
Divide both side by 1.66
s = 256/1.66
s = 154.22 m
Therefore, the distance travelled by the car before coming to rest is 154.22 m.
A man weighing 80kg is standing on a trolley weighing
320kg. The trolley resting on smooth horizontal rails. If
the man starts walking on the trolley along the rails with
a speed of 1ms", then his displacement relative to the
ground after 4 second is
1) 4.8 m 2) 4 m 3) 3.2 m 4) 2.8 m
Answer:
Net displacement = 3.2 m
Explanation:
Given:
Mass of man = 80 kg
Mass of trolley = 320 kg
Speed = 1 m/s
Time = 4 sec
Computation:
Displacement by man = 1 m/s × 4 sec
Displacement by man = 4 m
Net ext force (trolley) = com at rest
So,
320 × X = 80(4 - X)
32X = 32 - 8X
40X = 32
X = 0.8 m
Net displacement = 4 m - 0.8 m
Net displacement = 3.2 m
Answer:
3) 3.2 m
Explanation:
The computation of the displacement relative to the ground after 4 seconds is shown below:
Let us assume the following
Starting x coordinate is at the origin
As it does not involve any external force so x coordinated would remain unchanged
Now the separation between the man and the trolley is
[tex]= 4 \times 1[/tex]
= 4 m
And, we assume the displacement of man be x
So, for trolley it would be (4 -x)
Now we develop the equation which is
[tex]80 \times x = 320 \times (4 - x)[/tex]
x = 16 - 4x
Therefore x = 3.2 m