Explanation:
formula: Mass
Density x volume
2a) m=10kg v=0.3m³
10÷0.3=33.3 kg/m
2b) m = 160 kg V=0.1m³
160÷0.1=1600 kg/m
2c) m = 220 kg V = 0.02m³
220÷0.02=11000 kg/m
A wooden post has a volume of 0.025m³ and a mass of 20kg. Calculate its density in kg/m.
density = volume ÷ mass
20÷ 0.025=800 kg/m
Challenge: A rectangular concrete slab is 0.80m long, 0.60 m wide and 0.04m thick. Calculate its volume in m³.
Formula : Length x width x height = Volume
0.80 x 0.60 x 0.04 = 0.0192m³
B) The mass of the concrete slab is 180 kg. Calculate its density in kg/m.
density = volume ÷ mass
180 ÷ 0.0192 = 9375 kg/m
Which of the following equations correctly models a balanced single replacement reaction?
Answer:
d
Explanation:
is the answer
b. What is the man's weight on Mars where the acceleration due to gravity is
3.7 m/s2 ? Show your answer in both Newtons and pounds.
Answer:
How much is the mass of man?
HELP ME PLEASEE!!!THIS IS SCIENCE
Answer:
B.
Explanation:
ASAP
A spring is stretched downward by a certain length and, as a result, exerts a
force in the upward direction. What happens to the force exerted by the
spring if the length by which it is stretched is reduced by half?
O A. The force exerted by the spring is reduced by half.
B. The force exerted by the spring is doubled.
O C. The force exerted by the spring reduced by one quarter.
O D. The force exerted by the spring remains unchanged.
Answer:
A
Explanation:
Hooke's law! F(spring)=-kx
There's no tricky square law here. The spring constant doesn't change, only x (distance stretched) changes. Therefore, if distance is halved, Force will be halved.
How can you defined work done in term of kinetic energy, potential energy, and the force?
PLS HELP!! I will make brainliest!!
Which process is an example of a chemical reaction?
a. an iron nail rusting
b. bath water cooling while you take a bath
c. a piece of metal being heated until it expands
d. a glass window breaking when hit with a baseball
Answer:
Rusting!
Explanation:
Rusting is a chemical reaction because it is the process of oxidation of a metal.
Answer:
rusting
Explanation:
You are in a car traveling at 20 m/s. An ambulance is behind you traveling 35 m/s in the same direction. What frequency do you hear if the siren has a frequency of 550 Hz?
Answer:
The frequency heard is 576.78 Hz
Explanation:
The Doppler effect is defined as the apparent frequency change of a wave produced by the relative movement of the source with respect to its observer. In other words, this effect is the change in the perceived frequency of any wave motion when the sender and receiver, or observer, move relative to each other.
This is what happens in the first part of this problem, where the sender is train A and the receiver is train B. They are both moving in opposite directions. In this case, where both are in motion, the frequency perceived by the receiver will increase when receiver and transmitter increase their separation distance and will decrease whenever the separation distance between them is reduced. The following expression is considered the general case of the Doppler effect:
[tex]f'=f*\frac{v+-vR}{v+-vE}[/tex]
Where:
f ', f: Frequency perceived by the receiver and frequency emitted by the issuer respectively. Its unit of measurement in the International System (S.I.) is the hertz (Hz), which is the inverse unit of the second (1 Hz = 1 s-1)
v: Velocity of propagation of the wave in the medium. It is constant and depends on the characteristics of the medium. In this case, the speed of sound in air is considered to be 343 m / s
vR, vE: Speed of the receiver and the emitter respectively. Its unit of measure in the S.I. is the m / s
±, ∓:
We will use the + sign:
In the numerator if the receiver approaches the emitter In the denominator if the emitter moves away from the receiverWe will use the sign -:
In the numerator if the receiver moves away from the emitter In the denominator if the emitter approaches the receiverIn this case you are in a car traveling at 20 m/s and an ambulance is behind you traveling 35 m/s in the same direction.
In this case the receiver, you in the car, moves away from the emitter, while the emitter, the ambulance, approaches the receiver behind you in the same direction. So the frequency is calculated by the expression:
[tex]f'=f*\frac{v-vR}{v-vE}[/tex]
Being:
f= 550 Hzv=343 m/svR= 20 m/svE= 35 m/sand replacing:
[tex]f'=550 Hz*\frac{343 m/s-20 m/s}{343 m/s-35 m/s}[/tex]
you get:
f'= 576.78 Hz
The frequency heard is 576.78 Hz
What is the cheetahs momentum?
Answer:
Momentum is mass*velocity. Cheetah: 74*31 = 2294 kg-m/s.
what do fast-twitch and slow-twitch muscle fibers share in common
Answer:
Explanation:Slow-twitch muscle fibers support long distance endurance activities like marathon running, while fast-twitch muscle fibers support quick, powerful movements such as sprinting or weightlifting.
Which is NOT an example of evidence that shows a chemical reaction occurred?
change in color
change in temperature
change in shape
bubbles, fizzing
From an apple tree 2 metres high, a 100g mass apple fell of the tree, what work did it do?
Answer:
W = 1.96 J
Explanation:
Given that,
The mass of an Apple, m = 100 g = 0.1 kg
It fell from 2 metres high tree.
We need to find the work done by it. The work done is given by :
[tex]W=mgh\\\\W=0.1\times 9.8\times 2\\W=1.96\ J[/tex]
So, the required work done is 1.96 J.
What made heliocentrism scientific?
1) A 2.5 kg ball strikes a wall with a velocity of 8.5 m/s to the left. The ball bounces off with a
velocity of 7.5 m/s to the right. If the ball is in contact with the wall for 0.25 s, what is the
constant force exerted on the ball by the wall?
Answer:
Force = -10 Newton.
Explanation:
Given the following data;
Initial velocity = 8.5m/s
Final velocity = 7.5m/s
Time = 0.25 seconds
Mass = 2.5kg
To find the force exerted;
First of all, we would determine the acceleration of the ball;
Acceleration = (v - u)/t
Acceleration =(7.5 - 8.5)/0.25
Acceleration = -1/0.25
Acceleration = -4 m/s²
Now, to find the force exerted;
Force = mass * acceleration
Force = 2.5 * -4
Force = -10 Newton
Note: The force is negative because it is an opposite reaction.
Explain What is electrical energy and why do we need this energy
Answer:
WHAT IS ELECTRICAL ENERGY?Electrical energy is the most convenient form of energy for most human uses. Electrical energy is easy use and move from one location to another, but it is almost impossible to store in any large quantity. It can be used for running computers and most appliances, home heating, and even transportation.ELECTRICITY is used by industry, households, and businesses—accounting for 18% of end use energy worldwide.Electrical energy is very convenient, and as a result more and more of the energy used by a high energy society is in the form of electricity, see figure 1. The rate of electrical energy use is growing faster than the rate of electricity use, see figure 2.WHY DO WE NEED ELECTRICAL ENERGY?Electrical energy is used throughout the world to power devices, appliances and methods of transportation utilized in daily life. To make things operate, electrical energy must be emitted from energy sources such as power plants, to enable an object to consume the power it needs to function.Use the picture to answer the question below-
Which change in wave properties would show as an increase in amplitude?
H E L P P P P
a force of 25N acts on an object. The work done by the force is 400J. How far dose the object move in the direction of the force?
A. 6.3cm
B. 16cm
C. 16m
D. 10km
The distance moved by the object in the direction of the force is equal to 16 m. Therefore, option (B) is correct.
What is the work?Work can be demonstrated as the energy employed when a force is exerted to move an object through a specific distance. The work done depends upon both the exerted force on the object and the displacement.
The action of the force when the object is moving in a straight line in the direction of the exerted force over a distance 'd'.
W= F ×d
Where 'd' is the displacement, 'F' is the applied force and W is the work done.
Given, the work done by the applied force, W = 400 J
The force applied on the object, F = 25 N
The distance moved by the object, d = W/F
d = 400/25
d = 16 m
Therefore, the object moves a distance of 16 m in the direction of the force.
Learn more about work, here:
brainly.com/question/13662169
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As time goes on, the ENTROPY in a closed system should increase. This is because of which Law?
A) Conservation of Energy
B) Conservation of Momentum
C) 1st Law of Thermodynamics
D) 2nd Law of Thermodynamics
E) None of these
Answer:
The answer is D
The second law of thermodynamics
Explain the different types of energy in a working wind turbine
Answer:
A wind turbine converts the kinetic energy of the wind into mechanical power.
The wind moves the turbine and the turbine produce energy.
Donna shines a flashlight and a laser pointer on a sheet of paper. She holds each device at an equal distance from the paper. How does the light hitting the paper from each device appear different?
The light from the flashlight lights up a larger area of the paper.
The light from the laser pointer lights up a larger area of the paper.
The light from the flashlight magnifies a larger area of the paper.
The light from the laser pointer magnifies a larger area of the paper.
Answer:
A the light on the flash light lights up a bigger area
I'm pretty sure this is right.
Explanation:
Answer:
a
Explanation:
When you stretch a spring, there is energy in the spring's
potential energy store. What word completes the sentence?
Answer:
field strength i think, I'm not that sure.
A battery sends a current through a metal wire.
The current in a wire is 3.7 A.
Calculate the charge that flows into the wire in 13 s
Answer:
I hope this a little bit.
PLS HELPP!! I will make brainliest!!
Nuclear reactions occur when the nuclei of two different atoms collide to produce products that are different from the starting substances. How is this similar to a chemical change?
a. a chemical change can easily be reversed.
b. in a chemical change, mass can be created
c. in a chemical change, energy can be created
d. in a chemical change, a new substance forms
Nuclear reactions are independent of the chemical form of the element.
Chemical reactions, on the other hand, involve only a rearrangement of electrons and do not involve changes in the nuclei.
D.
2. The weights of four objects with different masses have been calculated to show how much each object would weigh on four different planets.Based on the table, which object would have the largest mass and greatest weight on Earth?
Weights of Four Objects on Four Planets
Planet 1
B 10 N
C 1 N
D 20 N
Planet 2
A 10N
C 0.2 N
D 4 N
Planet 3
A 100 N
B 20 N
D 40 N
Planet 4
A 5 N
B 1N
C 0.1 N
Answer:
d
Explanation:
Which law best describes this behavior of gases in the Sun?
Answer:
The extreme pressure from the weight of the gases that make up the Sun raises the temperature of the core enough for the nuclear reactions to take place, Which law best describes this behavior of gases in the Sun? A. Charles law.
Explanation:
if it is helpful....... plzz like and follow
3 examples of newtrons 2 law
Explanation:
1) Kicking a ball.
2) Capture the ball by hand.
3) Push a car.
Please help me with this
Answer:
I can't really see it sorry
Shrill sound is of -------------- *
Higher frequency
Lower frequency
Higher amplitude
Lower amplitude
Answer:
Higher frequency.
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases. A student could verify this statement by measuring the time required for sound to travel a set distance through a solid, a liquid, and a gas.
Mathematically, the speed of a sound is given by the formula:
[tex] Speed = wavelength * frequency [/tex]
Generally, the frequency of a sound wave determines the pitch of the sound that would be heard.
A shrill sound refers to a type of sound that is typically sharp, high pitched and as such has higher frequency.
Hence, shrill sound is of higher frequency.
A car travels at 12 m/s. The car then accelerates at 3 m/s2 until it reaches a speed of 18m/s.
Use the formula: (final velocity)2 – (initial velocity)2 = 2 x acceleration * distance
Calculate the distance the car travels.
A
2 m
B
6 m
С
30 m
D
60 m
Answer:
С. 30 m
Explanation:
Given the following data;
Initial velocity, U = 12m/s
Final velocity, V = 18m/s
Acceleration, a = 3m/s²
To find the distance, we would use the third equation of motion;
V ² = U² + 2aS
Substituting into the equation, we have
18² = 12² + 2*3*S
324 = 144 + 6S
6S = 324 - 144
6S = 180
S = 180/6
Distance, S = 30 meters.
An arrow that is pulled back by a bow has which type of energy?
Answer:
Kinetic energy
Explanation:
Kinetic energy is the energy of motion, and the arrow is in motion.
Please answer quick - You find a chain of volcanoes along a coast on land, not too far inland from
the ocean. The region experiences frequent large earthquakes. What type of
plate boundary is this? What types of plates are involved? Where is this type of
boundary found in California?