When a wire is made thicker its resistance what?
1 answer:
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Answer:
the heat absorbed by the block of copper is 74368.476J
Explanation:
Hello!
To solve this problem use the first law of thermodynamics that states that the heat applied to a system is the difference between the initial and final energy considering that the mass and the specific heat do not change so we can infer the following equation
Q=mCp(T2-T1)
Where
Q=heat
m=mass=2.3kg
Cp=0.092 kcal/(kg C)=384.93J/kgK
T2=Final temperatura= 90C
T1= initial temperature=6 C
solving
the heat absorbed by the block of copper is 74368.476J
Answer: C) 200 N
Explanation:
The force is defined as:
Where:
is the mass of the object
is the acceleration
Then:
Finally:
Hence, the correct option is C.
Answer:
a. If an object's speed is constant, then its acceleration must be zero.
FALSE
As we know that acceleration is defined as the rate of change in velocity
so we can not say anything about the acceleration when speed is given to as and no information is given about velocity
b. If an object's acceleration is zero, then its speed must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant and hence speed is also constant
c. If an object's velocity is constant, then its speed must be constant.
TRUE
Since velocity is constant then it shows that its magnitude and direction both are constant so its speed is also constant.
d. If an object's acceleration is zero, its velocity must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity
Since we know that if acceleration is 0 then velocity must be constant
e. If an object's speed is constant, then its velocity must be constant.
FALSE
Speed is just the magnitude so we can not say about its direction and hence if speed is constant then velocity may or may not change