A) Joe is right because the electricity is changed to heat and light and is no longer electricity.
B)Ben is right because the Law of Conservation of Energy is a law and cannot be false.
C) Ben is right because the electricity from the light is transformed into heat and light.
D) Joe is right because all electrical lights and appliances use electricity.
2) Greg and Shawn are studying for a physical science test. Greg thinks that the kinetic energy of an object depends on the height and speed of an object, but Shawn thinks it depends on the mass of an object. Who is right and why?
A) Shawn is right. The mass of an object determines the inertia of the object. Increasing inertia is the only thing that will increase kinetic energy..
B) Both Greg and Shawn are correct since kinetic energy depends on mass, height and speed of an object.
C) Greg is right. Increasing the height or speed of an object increases the kinetic energy of an object.
D) Neither is completely right. Shawn is partly correct since kinetic energy depends on mass, but Greg is also partly right since it also depends on speed.
3) Dan got into his car in the middle of summer. When he sat on the hot black leather seats, he burned his legs. His sister said that conduction was the reason Dan burned his legs, but Dan blamed the sunshine and said it was radiation that caused him to get burned. Who was right and why?
A) Both Dan and his sister are right. The sun heated the car seats through radiation heat transfer, but then Dan touched the seat and the heat was conducted to his legs.
B) Dan's sister was correct because Dan's legs touched the car seats. That is an indicator of heat transfer by conduction.
C) Dan was right because the sun heated the car without touching it. That is radiation.
D) Dan's sister was right because conduction can transfer heat through both solids and fluids (such as air).
1) C) Ben is right because the electricity from the light is transformed into heat and light.
Explanation:
The Law of Conservation of Energy states that energy cannot be created nor destroyed, but only transformed.
In this particular example, energy is not destroyed. In fact, the electrical energy (produced, for instance, by the battery inside the torchlight) is converted into light (electromagnetic wave) and heat (thermal energy). So, Ben is right, because energy is just transformed into other types of energy.
2) D) Neither is completely right. Shawn is partly correct since kinetic energy depends on mass, but Greg is also partly right since it also depends on speed.
Explanation:
The kinetic energy of an object is given by:
where m is the mass of the object and v its speed. From the formula, we see that neither Shawn nor Greg is completely right, because the kinetic energy depends both on the mass and the speed, and:
- Greg only told about the speed
- Shawn only told about the mass
3) B) Dan's sister was correct because Dan's legs touched the car seats. That is an indicator of heat transfer by conduction.
Explanation:
Conduction is the method of heat transfer that occurs between two solid objects, when they are in contact with each other, and it is due to the collisions between the molecules of the two objects: when colliding, the molecules of the hotter object transfer part of their kinetic energy to the molecules of the colder object.
In this case, Dan legs are in contact with the car seat (which is at higher temperature), so heat is transferred from the seat to Dan legs by conduction.
3 is B my dude and the reason nobody answered is because thousands of questions are asked every day. So not every question can be answered. It doesn't have to do with being lazy.
couch has a mass of 55 kg, what is the acceleration of the couch?
O A. 5 m/s2 right
O B. 5 m/s2 left
O c. 1.4 m/s? right
O D. 1.4 m/s2 left
SUBMIT
Answer:
C. 1.4 m/s² right
Explanation:
Apply Newton's second law. Take right to be positive and left to be negative:
∑F = ma
175 N − 100 N = (55 kg) a
a = 1.4 m/s²
The couch accelerates to the right at 1.4 m/s².
To find the acceleration of the couch, use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. The net force is calculated by subtracting the forces applied by the two individuals pushing in opposite directions. By plugging in the given values and solving the equation, the acceleration of the couch is found to be approximately 1.4 m/s² to the right.
To find the acceleration of the couch, we need to use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the net force is the difference between the forces applied by Dale and Alex, since they are pushing in opposite directions.
The net force can be calculated as 175 N (force applied by Alex) minus 100 N (force applied by Dale), which equals 75 N. The mass of the couch is given as 55 kg. Plugging these values into the equation, we get:
Net force = mass × acceleration
75 N = 55 kg × acceleration
Dividing both sides of the equation by 55 kg gives us:
acceleration = 75 N ÷ 55 kg ≈ 1.4 m/s²
Since the net force is positive (to the right) and greater than zero, the acceleration of the couch is also to the right. Therefore, the correct answer is 1.4 m/s² right (option C).
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The reason that the sun changes colors at sunset is because small particles and molecules in the atmosphere change the direction of light ray causing them to scatter and resulting in a beautiful sunset.