Answer:
The answer would be A. The waves that heat a cup of water in a microwave oven
Challenge
Marks: 1
How much energy is transferred by a 500 watt heater that is on for 2
minutes?
Answer:
Explanation:
500 W = 500 J/s
500 J/s(2 min(60 s/min) = 60000 J
Why is acceleration of an object moving at a constant velocity always zero?
Answer:
If an object is moving with a constant velocity, then by definition it has zero acceleration. So there is no net force acting on the object. The total work done on the object is thus 0 (that's not to say that there isn't work done by individual forces on the object, but the sum is 0 ).
Explanation:
In the middle, when the object was changing position at a constant velocity, the acceleration was 0. This is because the object is no longer changing its velocity and is moving at a constant rate.
The surface temperature of our sun is about 5800 K, and the peak of its intensity curve is in the middle of the visible spectrum. Mammals have a body temperature of about 310 K. A star that appears reddish could have a surface temperature of:
Explanation:
i expected to use Stefan's law of heat exchange but the value you gave aren't conclusive.
I should say that the temperature of the star should be close to that of the sun because of the similarity in the intensity curves
(0.50kg)(6.0mls)+(1.00kg)(-12.00mls)
Answer:
-9.0 × 10-6 m3 kg
Explanation:
I'm not sure if that's what you're looking for nor do I know how to explain it.
Four men are pushing on a broken car. One man pushes on the car with 345 N, another with 203 N, another
with 291 N and 101 N. The friction between the car and road pushes in the opposite direction with a force of 940 N.
1.) Make a claim: What is the net force on the car?
2.) Cite evidence: What evidence supports your claim?
3.) Make a claim: Will the car move?
4.) Provide reasoning: Why do you say that?
Answer:
1. 3 N
2. The total force being put on the car by the men is 943 while the friction is going in the opposite direction with a force of 940.
3. Yes
4. The net force is not equal to zero
Explanation:
1. 345 + 203 + 291 + 101 = 943 + -940 = 3
Find the required angular speed, ω, of an ultracentrifuge for the radial acceleration of a point 1.60 cm from the axis to equal 300000 g (where g is the acceleration due to gravity).
Express your answer numerically in revolutions per minute.
Answer:
Explanation:
300000(9.8) = ω²(0.0160)
ω = 13555 rad/s
13555 rad/s (60 s/min/ 2π rad/rev) = 129,445 rev/min
Are these a Chemical or Physical Change??
1. Sodium Bicarbonate breaks down into sodium carbonate and water.
A. Chemical Change
B. Physical Change
2. Mercury is cooled until it is in the solid state.
A. Chemical Change
B. Physical Change
The change of sodium bicarbonate breaking down into sodium carbonate and water is a chemical change. The cooling of mercury until it is in the solid state is physical change. The correct option for 1 is A and for 2 is B.
What is chemical and physical change?A chemical change occurs as a consequence of a reaction, whereas a physical change occurs when transformation occurs forms but retains its chemical identity.
Chemical changes include burning, cooking, rusting, and rotting. Physical changes include boiling, melting, freezing, and shredding.
A physical change is required to a specimen of matter in which some of the material's properties change but the matter's identity does not.
Physical changes can be classified as either reversible or irreversible. Melting is a reversible physical change because the melted ice cube can be refrozen.
In the first case, sodium bicarbonate is breaking down and forming sodium carbonate and water, this implies a chemical change.
In the second case, mercury is just cooling down, changing its physical shape. So it is physical change.
Thus, the correct option for 1 is A and for 2 is B.
For more details regarding chemical and physical changes, visit:
https://brainly.com/question/11321843
#SPJ2
A 0.75 kg model car is moving west at a speed of 9.0 m/s when it collides head-on with a 2.00 kg model truck that is traveling east at a speed of 10.0 m/s. After the collision, the 0.75 kg model car is now moving east at 11 m/s. What is the speed and direction of the model truck after the collision?
Answer:
2.5 m/s east
Explanation:
Let east be the positive direction for velocity.
The change in momentum of the 0.75 kg model car is ...
m1·v2 -m1·v1 = (0.75 kg)(11 m/s) -(0.75 kg)(-9 m/s)
= (0.75 kg)(20 m/s) = 15 kg·m/s
The change in momentum of the 2.0 kg model car is the opposite of this, so the total change in momentum is zero.
m2·v2 -m2·v1 = (2 kg)(v2 m/s) -(2 kg)(10 m/s) = 2(v2 -10) kg·m/s
The required relation is ...
15 kg·m/s = -2(v2 -10) kg·m/s
-7.5 = v2 -10 . . . . divide by -2
2.5 = v2 . . . . . . . add 10
The velocity of the model truck after the collision is 2.5 m/s east.
What is Acceleration?
Answer:
Depends on what are you looking at. All of the following are valid definitions, it just depends on which way you are analizing the problem.
From a kinematics point of view:
Acceleration is, by definition, is a vector quantity that measures the rate of change of the rate of change in position (add brackets if it helps visualizing the idea). This leads to the following different definitions - which are more like means of calculating it
the second derivative of position with respect to time [tex]a = \ddot x= \frac{d}{dt}({\frac d{dt}} x)[/tex];the first derivative of velocity with respect to time [tex]a = \dot v = \frac d{dt} v[/tex].From a dinamics point of view
Acceleration is the effect of a force applied to a body, and measures the ratio of the force applied to a body of mass m and the mass itself (which is another formulation of Newton second law):
[tex]a = \frac Fm[/tex]
Acceleration is the rate of change of velocity
To define acceleration, We need to know more about motion.
Motion: This can be defined as the change in position of a body from one point to another. When an object accelerates, it undergoes motion.
Definition
Acceleration can be defined as the rate of change of velocity. The S.I unit of acceleration is meter-per-squared seconds. (m/s²)
The formula of acceleration is
a = (v-u)/t................. Equation 1⇒ Where:
a = accelerationu = initial velocityv = final velocityt = timeHence, Acceleration is the rate of change of velocity
Learn more about acceleration here: https://brainly.com/question/605631
Anyone know? plzz It's a grade.
Answer:
Gregor Mendal discovered the basic laws of inheritance he concluded that genes come in pairs and are are inherited from each parent. Rosalind Franklin discovered the structure of DNA(Deoxyribonucleic Acid), and RNA(Ribonucleic Acid). She also discovered about the double helix structure of DNA. She works on the composition of the human body and her discoveries were vast. Watson and Clark were one of the greatest genetic discoverers ever. They were the ones who rose modern molecular biology. In short terms, they were the ones concerned with how genes work and there role in DNA Replication.
Explanation:
The equation below can be used to calculate a change in gravitational potential energy. What units must be used for h? Give the full name, not the abbreviation.
e=m x g x h
Answer:
h = change in vertical position (height)
has units of distance.
Explanation:
The equation below can be used to calculate a change in gravitational potential energy then the units used for the height would be meters.
What is mechanical energy?
The sum of all the energy in motion (total kinetic energy) and all the energy that is stored in the system (total potential energy) is known as mechanical energy.
As given in the problem, the equation below can be used to calculate a change in gravitational potential energy, the units used for the height of the object would be in meters, which is the SI unit of the length
The gravitational potential energy = mass×acceleration ×height
Thus, the unit of height used in the gravitational potential energy formula would be meter.
To learn more about mechanical energy from here, refer to the link;
brainly.com/question/12319302
#SPJ2
(a / xy=2x+a)does anyone can solve this??
Answer:??
Answer:
Explanation:
a / xy = 2x + a
a = 2x²y + axy
a(1 - xy) = 2x²y
a = 2x²y / (1 - xy)
a / xy = 2x + a
a = 2x²y + axy
a = y(2x² + ax)
y = a / (2x² + ax)
a / xy = 2x + a
a = 2x²y + axy
a / xy = 2x + a
0 = 2yx² + ayx - a
x = (-ay ±√((ay)² - 4(2y)(-a))) / (2(2y))
x = (-ay ±√(a²y² + 8ay)) / 4y
You are driving your car around a roundabout when you get a flat tire and you decelerate at a constant rate to a stop. The diameter of the roundabout is 100m. It takes you 20 sec to come to a complete stop. While slowing down, you continue to drive in a circle and you stop halfway around the loop. What must your speed have been before the pop?
Answer:
2.5 meters per second
Explanation:
stops half way which is 50m and if its at a constant speed of 2.5 meters multiply that by the seconds and you get 50m
The speed depends on the distance and time. The speed before the pop is 2.5 m/s.
What is the speed?The speed of an object is defined as the total distance traveled by the object within a given time interval.
Given that the diameter of the roundabout is 100m. It takes you 20 sec to come to a complete stop.
While slowing down, you continue to drive in a circle and you stop halfway around the loop. It means that the half distance is 50 m. The speed is calculated as given below.
[tex]s = \dfrac {D}{t}[/tex]
[tex]s = \dfrac {50}{20}[/tex]
[tex]s = 2.5 \;\rm m/s[/tex]
Hence we can conclude that the speed before the pop is 2.5 m/s.
To know more about the speed, follow the link given below.
https://brainly.com/question/12759408.
Use the diagram of the pulley system to complete the statement.In this pulley system, the pulleys will _____ the mechanical force required to lift the block and will change the _____.
The pulleys will reduce the mechanical force (effort) required to lift the block and will change the mechanical advantage.
The pulley system is a type of simple machine which makes our work easier and faster by overcoming a large load when a small force (effort) is applied to it.
The efficiency of a machine is calculated as follows;
[tex]Eff = \frac{M.A}{V.R} \times 100\%[/tex]
where;
M.A is the mechanical advantage V.R is the velocity ratio[tex]M.A = \frac{load}{effort}[/tex]
The velocity ratio of a pulley system = number of pulleys
The velocity ratio of a pulley system increases with increase in the number of pulleys.
Thus, we can conclude that the pulleys will reduce the mechanical force (effort) required to lift the block and will change the mechanical advantage.
Learn more about velocity ratio of pulleys here: https://brainly.com/question/24785465
2. An object is falling under gravity with terminal velocity. What is happening to its speed?
A. It is decreasing to a lower value.
B. It is increasing
C. It is decreasing to zero.
D. It is staying constant.
Answer:
the speed of the object has become constant.
Explanation:
At terminal velocity, air resistance equals in magnitude the weight of the falling object. Because the two are oppositely directed forces, the total force on the object is zero, and the speed of the object has become constant.
Answer This!!!!!!
I'll give brainliest to whoever gets it right.
And 100 Points!
Answer: Time (days) = 88, the (mass) = 0.2180
Explanation:
Time (days) = 88, the (mass) = 0.2180
A .223 rifle bullet, traveling at 370.m/s, hits a block of pine wood, and goes in, to a depth of 0.130m. The mass of the bullet is 1.75g (mass = 0.00175kg). Assume a constant slowing force. (A) What is the acceleration that the bullet experiences as it comes to a stop? (B) How much time is required for the bullet to stop? (C) What force, in Newtons, does the wood exert on the bullet?
Answer:
Explanation:
A)
v² = u² + 2as
a = (v² - u²) / 2s
a = (0² - 370²) / (2(0.130))
a = -526,538 m/s²
B)
t = v/a
t = 370 / 526538
t = 0.0007027... s or 0.7 ms
C)
F = ma
F = 0.00175(526,538) = 921.442307... = 921 N
someone plz help
An object accelerates from rest to 93 m/s over a distance of 49 m. What acceleration did it experience?
Answer:
Explanation:
v² = u² + 2as
a = (v² - u²) / 2s
a = (93² - 0²) / (2(49))
a = 88.255102...
a = 88 m/s²
Use the circuit diagram to decide if the lightbulb will
light. Justify your answer.
Answer:
The light bulb will NOT light because the lower switch being closed makes a short circuit. The light will have a high resistance and the electricity will choose to flow the easiest way possible through the low resistance wires.
Explanation:
A circular disk of radius 0.200 m rotates at a constant angular speed of 2.50 rev/s. What is the centripetal acceleration (in m/s2) of a point on the edge of the disk?
[tex]a_c = 3.14\:\text{m/s}^2[/tex]
Explanation:
First, we need to convert the given angular speed [tex]\omega[/tex] from rev/s to rad/s:
[tex]2.50\:\dfrac{\text{rev}}{\text{s}}×\dfrac{2\pi\:\text{rad}}{1\:\text{rev}} = 15.7\:\text{rad/s}[/tex]
The centripetal acceleration [tex]a_c[/tex] is defined as
[tex]a_c = \dfrac{v^2}{r}[/tex]
Recall that [tex]v = r\omega[/tex] so we can write [tex]a_c[/tex] as
[tex]a_c = \dfrac{(r\omega)^2}{r} = \omega^2r[/tex]
[tex]\;\;\;\;\;=(15.7\:\text{rad/s})^2(0.200\:\text{m}) = 3.14\:\text{m/s}^2[/tex]
all pressure topics in physics
In order to create a charged object, you need to ________.
Compare the time it
takes the light to travel from your
teacher to your eye with the time
it takes sound to travel the same
distance.
Answer:
Light takes less time than sound.
Explanation:
Let's say, the teacher and the student are at a distance "d" from each other.
The medium around them would be air.
And,
The speed of light in air is approx. 3× 10⁸ m/s
while, the speed of sound in air is approx. 330 m/s
We have a formula that establishes the relation between speed, distance and time.
[tex] \boxed{ \mathsf{speed = \frac{distance}{time} }}[/tex]
Our hunt for time — Speed in both the scenarios is known to us whereas the distance is same.
Sound
[tex] \mathsf{330 = \frac{d}{time_{s}} }[/tex]
[tex] \underline{\mathsf{time _{s} = \frac{d}{330} }}[/tex]
Light
[tex] \mathsf{3 \times {10}^{8} = \frac{d}{time _{l} } }[/tex]
[tex] \underline{ \mathsf{ time _{l} = \frac{d}{3 \times {10}^{8}} }}[/tex]
The best way of comparison is finding their ratio.
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ \frac{d}{330} }{ \frac{d}{3 \times {10}^{8} } } }[/tex]
simplifying the fraction
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{d \times (3 \times {10}^{8} )}{330 \times d}}[/tex]
d gets canceled and we're left with the following expression
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ (3 \times10 \times {10}^{7} )}{330}}[/tex]
30, being a common factor in the numerator as well as denominator, gets canceled out. and in its place remains 1/ 11
(why?
=> 30÷330 = 1÷11)
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ 1\times {10}^{7} }{11}}[/tex]
taking timeₛ to the numerator on the other side.
[tex] \implies \mathsf{time_{s} = \frac{ 1\times {10}^{7} }{11}\times time_{l}}[/tex]
Therefore, we get timeₛ is approx. 10⁶ times the timeₗ.
That's a big difference, no wonder light's way much faster than sound.
As lesser the time taken to cover a distance, faster is the wave.
The sound takes about 874,000 times MORE time than the light takes.
Tony brought 9 2/3pitchers of juice to a volleyball game, and the players drank3 7/8pitchers of it. How much juice is left?
Rewrite the amounts as improper fractions:
9 2/3 = 29/3
3 7/8 = 31/8
Rewrite both fractions with a common denominator
29/3 = 232/24
31/8 = 93/24
Now subtract: 232/24 - 93/24 = 139/24
Rewrite as a proper fraction: 5 19/24
Answer 5 19/24
If you are good at activities that require agility, what are you able to do well?
1.maintain your heart rate in the upper ranges
2.quickly change the direction of your movement
3.hold a difficult position for a long period of time
4.strategize about the best way to win a game
Answer:
2.quickly change the direction of your movement
Explanation:
Which of the following waves DO NOT require a medium to travel?
Answer:
hey man, think you forgot to put the questions
Telescopes work by using optics with true or false
Answer: true
its making me add 20 word so here they are g g g g g g g gg g t
Answer: its FALSE
Explanation:
Telescopes work by using optics with light is false, just took the quiz.
A car starting from rest has a constant acceleration of 5 m/s2. How long will it take to reach a speed of 20 m/s
Answer:
Explanation:
v = u + at
20 = 0 + 5t
t = 20/5
t = 4 s
Which statement about diffraction is correct?
A. Sound waves bend around the corners of various obstacles.
B. Sound waves can only travel in straight lines.
C. The amplitudes of two waves combine to appear as a wave smaller than the individual waves.
D. The amplitudes of two waves combine to appear as one big wave.
Answer:
I think A
Explanation:
Which statement about diffraction is correct?
A. Sound waves bend around the corners of various obstacles.
B. Sound waves can only travel in straight lines.
C. The amplitudes of two waves combine to appear as a wave smaller than the individual waves.
D. The amplitudes of two waves combine to appear as one big wave.
a stone is thrown down off a bridge with a velocity of 22 m/s. what is its velocity after 1.5 seconds has passed?
Answer:
Velocity of the stone after 1.5 seconds has passed = 37 m/s
Explanation:
Initial velocity (u) = 22 m/s
Time (t) = 1.5 sec
Acceleration due to gravity (g) = 10 m/s²
By using kinematics equation:
v = u + gt
v = 22 + 10 × 1.5
v = 22 + 15
v = 37 m/s
Final velocity (v) = 37 m/s