Answer:
Explanation:
Without friction, a roller coaster continuously converts potential energy to kinetic energy and back again. Total energy will be constant.
Let m be the mass of the car and ground level is the origin.
on the 5.5 m hill, total energy is
E = PE + KE
E = mgh + ½mv²
E = m(9.8)(5.5) + ½m(9.3)² = 97m J
a) The maximum height will occur when the total energy is all potential energy.
E = mgh
h = E/mg
h = 97m/m(9.8) = 9.9 m
As this value is greater than the height of the third hill at 5.5 + 4.0 = 9.5 m The car will cross the last hill with some remaining velocity in kinetic energy.
b) As 9.5 m is greater than 9.3 m, the 9.5 m hill will have more of the total energy of the system as potential energy, This mean there is less kinetic energy and therefore less velocity (and speed) on top of the 9.5 m hill.
c) KE = E - PE
KE = 97m - m(9.8)(9.5 - 1.0)
KE = 97m = 83.3m
KE = 13.7m = ½mv²
v² = √(2(13.7)
v = 5.2345...
v = 5.2 m/s
An empty cylindrical barrel is open at one end and rolls without slipping straight down a hill. The barrel has a mass of 15.0 kg, a radius of 0.400 m, and a length of 0.800 m. The mass of the end of the barrel equals a fourth of the mass of its side, and the thickness of the barrel is negligible. The acceleration due to gravity is =9.80 m/s2.
What is the translational speed f of the barrel at the bottom of the hill if released from rest at a height of 33.0 m above the bottom?
Hi there!
We can use work and energy to solve this problem.
We know that:
Ei = Ef
Ei = Potential energy = mgh
Ef = Rotational kinetic + Translational kinetic = 1/2Iω² + 1/2mv²
The barrel is comprised of a hollow cylinder and disk-shaped bottom, so:
I (hollow cylinder) = mr²
I (disk) = 1/2mr²
Calculate the moment of inertias of each.
Since the mass on the base is one-fourth of its side:
x = mass of side
x + x/4 = 15
4x + x = 60
5x = 60
x = 12 kg
end mass = 3 kg
Solve for each moment of inertia:
Side: (12)(0.4²) = 1.92 Kgm²
Bottom: 1/2(3)(0.4²) = 0.24 Kgm²
Side + bottom = 2.16 Kgm²
We can now solve:
mgh = 1/2mv² + 1/2(2.16)v²/r²
(15)(9.8)(33) = 1/2(15)v² + 1/2(13.5)v²
4851 = 14.25v²
v = 18.45 m/s
If you drop your keys from the tallest building in San Antonio, how fast will
they be falling after 3 seconds?
9.8 m/s
0 14,7 m/s
29.4 m/s
44,1 m/s
Hi there!
We can use the equation:
v = at, where in this instance:
v = velocity (m/s)
a = acceleration due to gravity (m/s²)
t = time (s)
g ≈ 9.8 m/s², so:
v = 9.8(3) = 29.4 m/s
How fast would a(n) 75 kg man need to run in order to have the same kinetic energy as an 8.0 g bullet fired at 390 m/s
Answer:
Explanation:
½(75)v² = ½(0.008)390²
v² = (0.008)390²/75
v² = 16.224
v = 4.027...
v = 4.0 m/s
Peregrine falcons, which can dive at 200 mph (90 m/s), grab prey birds from the air. The impact usually kills the prey. Suppose a 480 g falcon diving at 75 m/s strikes a 240 g pigeon, grabbing it in her talons. We can assume that the slow-flying pigeon is stationary. The collision between the birds lasts 15 ms.
Answer:
What is the average force of collision?
Explanation:
The velocity of the combined mass after impact is found by conservation of momentum
0.480(75) + 0.240(0) = (0.480 + 0.240)v
v = 50 m/s
An impulse results in a change of momentum
FΔt = mΔv
F = mΔv/Δt
for the pigeon
F = 0.240(50 - 0)/0.015
F = 800 N
for the falcon
F = 0.480(50 - 75)/0.015
F = -800 N
The final speed(v) of the Peregrine falcons and pigeon is 50 m/s
The objective of this question is to determine the final speed(v) of the Peregrine falcons and pigeon
From the information given:
the mass of the falcon m_f = 480 gthe speed of the falcon v_f = 75 m/sthe mass of the pigeon m_p = 240 gthe collision time = 15 ms = 0.015 sAccording to the conservation of momentum, we can say that the totality of momentum before and after the collision is the same. As such;
[tex]\mathbf{m_fv_f = (m_f+m_p) v}[/tex]
[tex]\mathbf{480 g \times 75 m/s = (480 + 240) \ g \times v}[/tex]
[tex]\mathbf{v = \dfrac{480 g \times 75 m/s}{(480 + 240) \ g}}[/tex]
[tex]\mathbf{v = \dfrac{36000 \ m/s}{ 720}}[/tex]
v = 50 m/s
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Two airplanes taxi as they approach the terminal. Plane 1 taxies with a speed of 13 m/s due north. Plane 2 taxies with a speed of 8.5 m/s in a direction 20 ∘ north of west.
Part A
What is the magnitude of the velocity of plane 1 relative to plane 2?
Part B
What is the direction of the velocity of plane 1 relative to plane 2?
Part C
What are the magnitude of the velocity of plane 2 relative to plane 1?
Answer:
Explanation:
Plane 2 is moving north at
8.5sin20 = 2.9 m/s
Plane 2 is moving west at
8.5cos20 = 8.0 m/s
Part A
v = √((13 - 2.9)² + 8.0²) = 12.876... 13 m/s
Part B
θ = arctan((13 - 2.9) / 8.0) = 51.617... 52° N of E
Part C
13 m/s 52° S of W
relative velocity magnitude is independent of reference frame
What is speed of sound in air?
Answer:
speed of sound, speed at which sound waves propagate through different materials. In particular, for dry air at a temperature of 0 °C (32 °F), the modern value for the speed of sound is 331.29 metres (1,086.9 feet) per second
An object moving at a constant velocity of 5.4 m/s travels for 12 s. How far will it move during that time?
Free-fall Acceleration is -10 m/s^2
Answer:
we know that
s=vt
given
v=5.4 m/s
t=12 s
s=5.4 m/s*12 s=64.8m
Explanation:
Hope this helps:)
Can someone PLEASE help me??
E TRUE OR FALSE: Write the word TRUE if the statement is correct, and FALSE if it is not. (3 points each). Write your answer on a separate sheet of paper. 1. Most EM waves has the same speed. 2. EM waves travel at the speed of 4x108 m/s. 3. Electromagnetic waves are transverse waves consisting of changing electric fields and changing magnetic fields. 4. Electromagnetic waves transfer energy through a vacuum. 5. A wave is a disturbance that transfers energy .what the answer?
Answer:
TRUE
FALSE
TRUE
TRUE
TRUE
TRUE
Explanation:
1. Most EM waves has the same speed. True
2. EM waves travel at the speed of 4x108 m/s. False
3. Electromagnetic waves are transverse waves consisting of changing electric fields and changing magnetic fields. True
4. Electromagnetic waves transfer energy through a vacuum. True
5. A wave is a disturbance that transfers energy. True
A stomp rocket takes 3.1 seconds to reach its maximum height.
- What is its initial velocity? (Do not use units. If the answer is negative, please put a
negative sign in front of the answer.)
- What is its maximum height? (Do not use units. If the answer is negative, please put a
negative sign in front of the answer.)
Answer:
Explanation:
Ignoring air resistance the time to rise will equal the time to fall and initial velocity will be the same magnitude as final velocity just before impact.
v = at
v = 9.8(3.1)
v = 30.38
v = 30 m/s
max height can be found knowing the velocity is zero at the top of its flight.
v² = u² + 2as
s = (v² - u²) / 2a
s = (0.00² - 30.38²) / (2(-9.8))
s = 47.089
s = 47 m
A stomp rocket takes 3.1 seconds to reach its maximum height then the initial velocity is given as v = 30 m/s and maximum height is 47.089 m.
What is Velocity?Velocity is defined as rate of change of position with respect to time.
SI unit of velocity is m/sec. Velocity is a vector quantity.
Given that in the question time taken by rocket to reach maximum height is 3.1 sec. Ignoring air resistance the time to rise will equal the time to fall and initial velocity will be the same magnitude as final velocity just before impact.
v = at
v = 9.8(3.1)
v = 30.38
v = 30 m/s
Max height can be found knowing the velocity is zero at the top of its flight.
v² = u² + 2as
s = (v² - u²) / 2a
s = (0.00² - 30.38²) / (2(-9.8))
s = 47.089
s = 47 m
So, the initial velocity is given as v = 30 m/s and maximum height is 47.089 m.
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Suppose you lift a 17 kg k g box by a height of 1.0 m m . How much work do you do in lifting the box
Answer:
17 J
Explanation:
work done= force X distance moved
A circular coil having 60 turns has a radius of 75 mm. What current must exist in the coil
to produce a magnetic field of 300 μT at the center of the coil?
Answer:
Explanation:
Step 1 of 4
CONCEPT:
The mathematical expression for magnetic field B at center of a coil:
Here, is the current in the coil, N is the number of turns of the coil, is the permeability of the free space and is radius of the coil.
Rearrange above equation for current in the coil.
What is the formula of [tex]\underline{force}[/tex]in physics?
The formula of force is F = ma.
Force: This can be defined as the product of mass and acceleration. The S.I unit of force is Newton (N). Force is a vector quantity
Types of force
Friction forcePushPullUpthrustTensional force.
⇒ The formula of force is
F = ma................ Equation 1
⇒ Where:
F = forcem = mass of the bodya = accelerationHence, the formula of force is F = ma.
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Before looking at the formula, Lets understand what is force?
Force:- Force can be defined as the cause of motion of an object. Force can change the shape, direction and velocity of an object.It's SI unit is NewtonThe formula used to find force is:
[tex] \sf \nrightarrow \: F=m×a[/tex]
Where,
F is forceM is mass of the bodyA is accelerationEquation in words:- Force applied on an object is directly proportional or equal to the product of the mass of object and the acceleration of object.
A solar collector for a hot water system absorbs solar radiation at the rate of 660 W/m^2
. Its collecting area is 3.8m^2 . Cold water at 15degrees enters the collector. What volume of
water per minute at an output temperature of 60 degrees can this collector deliver?
This question involves the concepts of the law of conservation of energy and specific heat capacity.
This collector can deliver "7.96 x 10⁻⁴ m³/min" of water at an output temperature of 60°C.
According to the law of conservation of energy:
Solar Energy = Energy Required to raise the temperature of the water
Solar Power = Energy Required to raise the temperature of the water
[tex]IA=\frac{mC\Delta T}{t}\\\\\frac{m}{t}=\frac{IA}{C\Delta}[/tex]
where,
[tex]\frac{m}{t}[/tex] = mass flow rate = ?
I = solar radiation = 660 W/m²
A = Area = 3.8 m²
ΔT = change in temperature = 60°C - 15°C = 45°C
C = specific heat capacity = 4200 J/kg.°C
Therefore,
[tex]\frac{m}{t}=\frac{(660\ W/m^2)(3.8\ m^2)}{(4200\ J/kg.^oC)(45^oC)}\\\\\frac{m}{t}=(0.0133\ kg/s)(\frac{60\ s}{1\ min})\\\\\frac{m}{t}=0.796\ kg/min[/tex]
Now, the volume flow rate will be:
[tex]\frac{V}{t}=\frac{(\frac{m}{t})}{(density\ of\ water)}=\frac{(0.796\ kg/min)}{(1000\ kg/m^3)}\\\\\frac{V}{t}=7.96\ x\ 10^{-4}\ m^3/min[/tex]
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The attached picture explains the law of conservation of energy.
Swim swim swim swim swim swim swim swim swim swim swim swim.
The_____ scale is called an absolute temperature scale, and its zero point is called absolute zero.
Kelvin
Fahrenheit
Celsius
The Celcius Scale is called an absolute Temperature scale,and it's zero point called absolute zero
_______________
14 The radius of gyration of a body about an axis &ta
distance 6 cm from its centre of mass is 10 cm.
Then, its radius of gyration about a parallel axis
through its centre of mass will be
(a) 80 cm (b) 8 cm (c) 0.8 cm (d) 0.08 cm
Correct option is B 8 cm.
Let radius of gyration for the axis not passing through center of mass be r and that for the axis passing through the center of mass be k and the distance between the two parallel axes be a.
Parallel axes theorem gives:
[tex] {mr}^{2} = m( {k}^{2} + {a}^{2} ) \\ ⇒ {r}^{2} = {k}^{2} + a {}^{2} [/tex][tex]⇒k = \sqrt{ {10}^{2} - {6}^{2} } = 8cm.[/tex]Thus, option B is the correct answer.
Look at the simple machine shown below to determine the mechanical advantage
Answer:
A
Explanation:
When does your body conduct current more readily?
when it is hot
when it is dry
when it is cold
when it is wet
Answer:
When you are wet or you are sweating current passes easily.
Explanation:
wetness increases conductivity. therefore 'when it is wet'.
Wrte down the effect of humidity and temperature in the speed of sound....
Explanation:
the speed of sound is affected by temperature and humidity
What state of matter is jelly?
Answer:
Hey mate.....
Explanation:
This is ur answer.....
SolidsJelly is a colloid where colloidal particles are solids which are dispersed in the liquid. Jelly is a fluid which can not be considered as a particular one kind of state. It is in the category of 'gel' which is a colloidal form.
Hope it helps!
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A ball is thrown up into the air. When it gets to the very top,
what kind of energy does it have?
At the highest attitude, the velocity of the ball is 0 m/s, so the kinetic energy is 0 as well.
Hence the answer is potential energy because it doesn't depend on velocity .
PLEASE HELP!
A 2457 kg car moves with initial speed of 18 ms-?. It is stopped in 62 m by its brakes.
How much work is done by the brakes?
Answer:
Explanation:
The work of the brakes will equal the initial kinetic energy of the car
Fd = ½mv²
F = mv²/2d
F = 2457(18²) / (2(62))
F = 6,419.903...
F = 6.4 kN
can someone please help no.1,2,3
Answer:
12345678910i don't know
Find the time it takes for an object dropped from a building and reaches a final velocity of 20 m/s downward?
I need the formula
Answer:
Explanation:
v = at
t = v/a
t = 20 m/s / 9.8 m/s²
t = 2.0408163...
t = 2.0 s
An object at rest on a flat, horizontal surface explodes into two fragments, one seven times as massive as the other. The heavier fragment slides 5.60 mm before stopping. How far does the lighter fragment slide
Answer:
M1 + M2 = 0 total momentum before explosion = momentum after explosion where M1 is the lighter fragment
M1 V1 + 7 M1 V2 = 0
V2 = -V1 / 7
The lighter fragment will slide 7 times as far - 39.2 mm because it must have 7 times as much velocity - assuming the distance slid is proportional to the original velocity
why does air pressure decrease with increasing altitude?
A 2.0 kg particle moving along the z-axis experiences the
force shown in (Figure 1). The particle's velocity is
3.0 m/s at x = 0 m.
A) At what point on the x axis does the particle have a turning point?
At point x = 0, the particle accelerates. Since there will be change of velocity at that point. The the force of the particle will change from negative sign to positive sign according to the given figure, we can therefore conclude that the particle will have a turning point at point x = 0.
Given that a 2.0 kg particle moving along the z-axis experiences the force shown in a given figure.
Force is the product of mass and acceleration. While acceleration is the rate of change of velocity. Both the force and acceleration are vector quantities. They have both magnitude and direction.
If the particle's velocity is 3.0 m/s at x = 0 m, that mean that the particle experience change of velocity at point x = 0. Since the the force of the particle will change from negative sign to positive sign according to the given figure, we can therefore conclude that the particle will have a turning point at point x = 0.
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Assume that two cars have the same kinetic energy, but that the red car has twice the speed of the blue car. We then know that the red car has ____ mass as the blue car.
Answer:
equal
Explanation:
Children in a tree house lift a small dog in a basket 3.85 m up to their house. If it takes 201 J of work to do this, what is the combined mass of the dog and basket
Answer:
Explanation:
The work will equal the increase in potential energy.
PE = mgh
m = PE/gh = W/gh = 201/(9.81(3.85)) = 5.32 kg