Answer:
Explanation:
The formula for Kinetic Energy is
[tex]KE=\frac{1}{2}mv^2[/tex]. Filling in:
[tex]KE=\frac{1}{2}(1200)(20)^2[/tex] It looks like we only need 1 significant digit here but I'll give you 2 and you can round how you want.
KE = 2.4 × 10⁵ J
A small object is launched with a velocity 26.2 m/s at an angle 35.8 degrees above the horizontal from the top of a building with height 46.4 m. Air resistance is negligible during the motion of the object. How long (in seconds) does it take the object to reach the ground
Answer:
Explanation:
The angle here makes this a very interesting problem. We will use only the y-dimension information since we are given nothing pertinent in the x-dimension. Nothing there is useful to solving this problem. We are given (and know from experience) the following:
θ = 35.8°
v₀ = 26.2 m/s
Δx = -46.4 m
a = -9.8 m/s/s
t = ???
Time is our main unknown. The displacement is negative because, in the end, the small object will end up BELOW the point from which it is launched. That's important!!
Another thing we need to understand is that the velocity we are given is a "blanket" velocity; it is neither the upwards velocity nor the horizontal velocity. That's for us to find out using either cos or sin. In the y-dimension, we use the sin identity to find the upwards velocity (which is VERY different from the horizontal velocity {unless we are dealing with a 45 degree angle where sin and cos are the same}). So first we need to find the initial velocity in this dimension specifically:
26.2sin35.8 = 15.3 m/s
That's the initial velocity we will use in the problem now. The equation for this is:
Δx = v₀t + [tex]\frac{1}{2}at^2[/tex] and filling in the given info:
[tex]-46.4=15.3t+\frac{1}{2}(-9.8)t^2[/tex] It looks like this will have to be factored if we are going to solve for t. Get everything on one side and factor the resulting quadratic:
[tex]-4.9t^2+15.3t+46.4=0[/tex] and factoring that gives you 2 values for t:
t = -1.9 sec and t = 5.0 sec
Since we all know that time can NEVER be negative, t = 5.0 sec.
‘The Universe is expanding.’ Justify this statement with the Big bang model of universe and Hubble’s Law.
Explanation:
The expansion of the universe is the increase in distance between any two given ... Metric expansion is a key feature of Big Bang cosmology, is modeled mathematically with the ...
Reason whether or not work is done in the following cases:
A. a basketball player shoots a free throw.
B. a peasant pulls a rope tied to a donkey without being able to displace it from its position.
Answer:
A work is done because the object moved
B no work is done because the donkey didnt move
Explanation:
on what factor does speed of sound depend
Answer:
For sound waves to travel, there is a requirement of medium and density of the medium is considered to be one of the factors on which the speed of sound depends. When the medium is dense, the molecules in the medium are closely packed which means that the sound travels faster.
Explanation:
a toy car takes .60 seconds to travel .30 meters after it is released from rest. what is the acceleration of the toy car?
Juan's mother drives 12.5 miles southwest to her favorite shopping mall. What is the velocity of her
automobile if she arrives at the mall in 7.25 minutes?
Answer:
v1= 12.5miles, t= -7.25m, a= 0
v= 1/2at^2
v= 1/2×
write the application of gravitational force
Answer:
Applications of Gravitational Force:
Gravity keeps your feet on the ground. Gravity holds the air down. Gravity makes the Earth roughly spherical. Gravity keeps the Moon (and all those artificial satellites) orbiting around the Earth. Gravity keeps the Earth orbiting around the Sun and the Sun orbiting around the galactic centre. Gravity creates the water pressure that runs hydroelectric turbines at the bottom of dams. Gravity brings the rain back down after it evaporates into the atmosphere.What does the geology of the two continents indicate about past events in Earth history?
Answer:
Explanation:
Rocks tell us a great deal about the Earth's history. Igneous rocks tell of past volcanic episodes and can also be used to age-date certain periods in the past. Sedimentary rocks often record past depositional environments (e.g deep ocean, shallow shelf, fluvial) and usually contain the most fossils from past ages.
What is the equation for density? NO LINKS
d = V/m
d= m + V
d= m x V
d= m/V
1. I get so much energy when I eat candy! What type of energy is this statement referring to?
O mechanical
O kinetic
O potential
O chemical
The answer is chemical
What if the World turned to Gold?
Answer:
We would all freeze at close to absolute zero and gold will not be worth anything
Explanation:
Ron weighs a bottle with a mass of 0.5 kilograms on a spring scale. The spring stretches by 1 centimeter. He then weighs a second bottle on the same spring scale. What is the mass of the second bottle, in kg, if the spring stretches by 2 cm
Answer:
1 kg
Explanation:
Applying,
Hook's law,
F = ke................. Equation 1
Where F = force, k = force constant of the spring, e = extension.
But from the question,
The weight of the bottle is the force acting on the spring scale
therefore,
mg = ke............ Equation 2
Where m = mass of the bottle, g = acceleration due to gravity.
make k the subject of the equation
k = mg/e............ Equation 3
Given: m = 0.5 kg, e = 1 cm = 0.01 m
Constant: g = 9.8 m/s²
k = (0.5×9.8)/0.01
k = 490 N/m
If the mass of the second bottle is weighed,
given: e = 2 cm = 0.02 m
subtitute into equation 1
m×9.8 = 490×0.02
9.8m = 9.8
m = 9.8/9.8
m = 1 kg.
Hence the mass of the second bottle is 1 kg
A 9 kg box is placed on a 6 m tall shelf. What will be the kinetic energy of the box right before it hits the ground? (use g = 10 m/s/s)
Answer:
540 J
Explanation:
U at top equals to K at bottom if it's an isolated system therefore U at top is equals to 540 J so we can assume that at 0m U=0 (mgh) therefore the box has gained some velocity due to the acceleration due to g and we can calculate it using 1/2mv²
what is the pressure at 5000 km below the surface of the earth
Answer:
The centre of the earth is harder to study than the centre of the sun." Temperatures in the lower mantle the reach around 3,000-3,500 degrees Celsius and the barometer reads about 125 gigapascals, about one and a quarter million times atmospheric pressure.
Explanation:
The atmospheric pressure of earth is 1 atm. As the height decreases, the pressure of the surface increases. Pressure increases about one atmosphere for every 10 meter depth of earth surface and water, hence, the pressure at 5000 km below approximately equal to 500 - 1000 atm.
What is pressure ?Pressure of a region is the force acting per unit area. The atmospheric pressure is generated by the gases and dust particles. As the heights from the surface increases, the temperature decreases and pressure also decreases.
Thus, in lower altitudes the pressure will be higher. The standard unit of pressure is atm. The normal atmospheric pressure is 1 atm. Other units are bar, pascal, torr etc.
Pressure increases about one atmosphere for every 10 meter depth of earth surface and water, hence, the pressure at 5000 km below approximately equal to 500 - 1000 atm.
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Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The length of each rod is 1.1 m, while the mass of each is 0.10 kg. One rod is held in place above the ground, and the other floats beneath it at a distance of 11 mm. Determine the current in the rods.
Answer:
220 A
Explanation:
The magnetic force on the floating rod due to the rod held close to the ground is F = BI₁L where B = magnetic field due to rod held close the ground = μ₀I₂/2πd where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, I₂ = current in rod close to ground and d = distance between both rods = 11 mm = 0.011 m. Also, I₁ = current in floating rod and L = length of rod = 1.1 m.
So, F = BI₁L
F = (μ₀I₂/2πd)I₁L
F = μ₀I₁I₂L/2πd
Given that the current in the rods are the same, I₁ = I₂ = I
So,
F = μ₀I²L/2πd
Now, the magnetic force on the floating rod equals its weight , W = mg where m = mass of rod = 0.10kg and g = acceleration due to gravity = 9.8 m/s²
So, F = W
μ₀I²L/2πd = mg
making I subject of the formula, we have
I² = 2πdmg/μ₀L
I = √(2πdmg/μ₀L)
substituting the values of the variables into the equation, we have
I = √(2π × 0.011 m × 0.1 kg × 9.8 m/s²/[4π × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2 × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2.2 × 10⁻⁷ H])
I = √(0.0049 × 10⁷kgm²/s²H)
I = √(0.049 × 10⁶kgm²/s²H)
I = 0.22 × 10³ A
I = 220 A
What is the normal force and gravitational force on a 55 kg person standing stationary?
Answer:
539.55 N for both
Explanation:
F=ma
Mass is given at 55kg
And when finding gravitational force gravity's constant is an acceleration of 9.81m/s
F=(55)(9.81)
F= 539.55 N (for both)
Normal force cancels out gravitational force that's why we don't fall throught the floor.
We push down on the floor due to gravitational force but normal force keeps us upright pushing an equal amount back.
The firing of a bullet by a rifle causes the rifle to recoil backwards. The speed of
the rifle's recoil is smaller than the bullet's forward speed because the___
A.)force against the rifle is relatively small
B.)speed is mainly concentrated in the bullet
C.)rifle has lots of mass
D.)momentum of the rifle is unchanged
Answer:c i.e. rifle has lots of mass
Explanation:It's because we know that the force of recoiling is same. But since the mass of rifle is very much greater than that of the bullet, it's balanced by the less speed of the recoiling of the rifle.
A positive charge is moving across a room from south to north. A magnetic field runs from east to west. In what direction is the magnetic force on the moving positive charge?
Answer:
the force is on the z axis, coming out of the blade
Explanation:
The direction of the magnetic force is given by the right hand rule,
For a positive charge, the thumb points in the direction of velocity, the other fingers extended in the direction of the magnetic field, and the palm points in the direction of force.
In this case.
Thumb points North
The fingers extended is in the east - west direction parallel to the blade
The palm is sticking out of the leaf, in the z direction
the answer is the force is on the z axis, coming out of the blade
Which of the following has the most kinetic energy?
A. A 25-kg fish tank sitting on a table
B. A 50-g fish swimming in a fish tank
C. A 7,500-kg car parked on a steep hill
D. A 50-kg Boulder suspended from a cliff
Answer:
The answer is B
Explanation:
Only things that are moving have kinetic energy, therefore B is the only correct answer
A beaker containing water at 80°C is placed on a piece of aluminum at 25°C. How will thermal energy transfer? O by conduction from the aluminum to the beaker O by convection from the aluminum to the beaker O by convection from the beaker to the aluminum O by conduction from the beaker to the aluminum
The thermal energy transfer will occur by convection from the aluminium to the beaker.
Thermal energy can be defined as the energy held in a system that is accountable for the overall temperature of the system.
Conduction is the process by which heat energy is transferred from one material or substance to another.
Convection is the transfer of heat in the fluid medium. e.g when a fluid is heated, heat energy is transferred into the fluid which causes a rise in the temperature of the fluid.
Since water is a fluid medium, the thermal energy transfer will occur by convection from the aluminium to the beaker.
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If a roller-coaster car has 40,000 J of gravitational potential energy when at rest on the top of a hill, how much kinetic energy does it have when it is ½ of the way down the hill?
=============================================
Work Shown:
PE = potential energy
KE = kinetic energy
m = mass
g = acceleration of gravity
h = height of the object
PE = m*g*h = 40,000 joules
---------
If the car is halfway down the hill, then that means the height of the car is h/2 instead of h
We can then say:
m*g*(h/2) = (m*g*h)/2 = (40,000)/2 = 20,000 J
is the amount of potential energy at this location. The amount of kinetic energy must be the remaining amount that adds to this, to get 40,000 J again.
Put another way: The 40,000 J of PE to start off with, when KE = 0, means we have a total energy of 40,000 J
---------
So,
PE+KE = total energy
PE+KE = 40,000 J
20,000 J + KE = 40,000 J
KE = (40,000 J) - (20,000 J)
KE = 20,000 J when the car is halfway down the hill.
The equivalent resistance of a complex circuit is usually determined by a dividing the sum of the individual resistances by the number of resistances. b adding and subtracting individual resistances. c inspection. d simplifying the circuit into groups of series and parallel circuits.
Answer:
d
Explanation:
we simplify the circuit into groups to obtain a complete circuit I.e series and parallel circuit
What is a core sample?
Answer:
it's a part of plate that moves with a plate that's the answer
Iron meteorites are interpreted as deriving from the cooled metallic core of a largeish asteroid. This is based upon:
Answer:
This is based upon the fact that meteorites are generally believed to have originated as solid debris from Larger bodies like meteoroid or asteroids
Explanation:
Iron meteorites are interpreted as deriving from the cooled metallic core of a larger asteroid , because meteorites are generally believed to have originated as solid debris from Larger bodies like meteoroid or asteroids that are located outside the planet but found their way into our planet .
A beam of light hits a mirror at an angel of 35 degrees. What is the angel that it bounces off at?
a. 55 degrees
b. 35 degrees
c. 90 degrees
Answer:
c
Explanation:
light refraction is a right angle
(c) The plastic tube is attached to a metal mast.
This would cause the metal mast to become positively charged.
Explain why there is a wire connecting the metal mast to the Earth.
can someone please help by answering the question and not write anything
Explanation:
Since the mast is a conductor and connected to the plastic so charge transfer takes place between the mast and the tube because the mast is connected to the ground with wire which is called grounded which means its potential is 0 equal to the ground so that charge can transfer from plastic tube to the ground. This is why the wire is used to connect the metal mast to the Earth.
If a sled has a mass of 4kg what is the force of gravity on the sled?
Answer:
Explanation:
Gravity pulls everything down at the same rate of 9.8 m/s/s. If you're looking for the normal force, which is the same as the weight of the object, we'll find that, just in case.
w = mg which says that the normal force/weight of an object is equal to its mass times the pull of gravity:
w = 4.0(9.8) so
w = 39N
The force between two charges is 1000 N. One has a charge of 2.0 x 10-5 C and one has a charge of 5.0 x 10-6 C. What is the distance between the charges?
Answer:
F= kq1q2÷r^2 r=√9x10^9 x 2.0 x 10^-5 x 5.0x 10^-6 ÷ 1000 ) the ansewer√300
3) Which has more translational energy?
A)A person running at 8 mi/hr
B)A person walking at 4mi/hr
C)They both have the same amount of translational energy
D)Neither has any translational energy
what is point mutation ?
Answer:
A point mutation or substitution is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome.
Hope it helps u