Answer:
a)-2m/s^2
b)27.2m/s
Explanation:
Hello! The first step to solve this problem is to find the mass of the block remembering that the definition of weight force is mass by gravity (g=9.8m / s ^ 2)
W=455N=weight
W=mg
W=455N=weight

The second step is to draw the free body diagram of the body (see attached image) and use Newton's second law that states that the sum of the forces is equal to mass by acceleration

for point b we use the equations of motion with constant acceleration to find the velocity

Where
Vf = final speed
Vo = Initial speed
=0
A = acceleration
=2m/s
X = displacement
=6.8m
Solving

The question is incomplete, the options are;
RI^2
I^2/R
R/I^2
R/V^2
RV^2
V^2/R
VI
VIR
Select all that apply
Answer:
P=RI^2
P=V^2/R
P=VI
Explanation:
Power is the rate at which energy is changing in a circuit. It is shown by the formulas outlined above from the group of answer choices. Since the current (I), voltage (V), and resistance (R) were mentioned in the question, any of three three formulas could be used to obtain the power drawn by the conductor.
Answer: A. Work is done on the system and heat is transferred from the system for a net decrease in internal energy.
Explanation:
A refrigerator is a device which dispenses heat from the close system to a warmer area or in the surrounding. By dispensing the heat the internal temperature of the refrigerator drops. The system of refrigerator violates the second law of thermodynamics. As it performs the work to cool the region instead of heating the region. The work is done on the system and the internal energy decreases and the heat energy is liberated to the surrounding area. A refrigerator is an open system.
Answer:
single replacement
Explanation:
In the question it says one element replaces another element which means there is only one replacement.
Yes, scientific method can be applied on many everyday activities to get a reasonable solution. Infact normally we are applying this method without having it in our knowledge that we are applying it.
For example: In morning we are going to office and we start the car, but it is not started.You turn the engine again and again but it simply donot works.
Observation (the state of defining a problem):
The car is not started
Hypothesis (A possible solution based on the information we already know):
The car is not started because it might be out of gas or there can be some other technical fault.
Experiment (testing of hypothesis by applying different methods of solving problem):
You get the fuel and put it inside the car but it still donot works and car didnot start. Experiment didnot get solution.
Analyze the results of data and test another hypothesis
You call a technician and he check with the car engine tries and finds out that the engine was out of order and needs repairing.
Draw conclusion:
The engine do not works when it is out of order and it is a cause of a car not being started.
<em>Now the theory and law making part can not be applied on this case but it is a part of scientific method.</em>
Hope it helps!