4. a poor insulator
If rest other things are kept constant or unchanged then a good conductor can be termed as a poor insulator.
Answer:
The final velocity of the object is,
= 27 m/s
Explanation:
Given,
The acceleration of the object, a = 1000 m/s²
The initial displacement of the object,
= 0 m
The final displacement of the object,
= 0.75 m
The initial velocity of the object will be,
= o m/s
The final velocity of the object,
= ?
The average velocity of the object,
v = (
-
)/ t
= 0.75 / t
The acceleration is given by the relation
a = v / t
1000 m/s² = 0.75 / t²
t² = 7.5 x 10⁻⁴
t = 0.027 s
Using the I equation of motion,
= u + at
Substituting the values
= 0 + 1000 x 0.027
= 27 m/s
Hence, the final velocity of the object is,
= 27 m/s
Answer:
C. The bug's change in momentum is equal to the car's change in momentum.
Explanation:
As we know by Newton's 2nd law
![F = \frac{\Delta P}{\Delta t}](https://tex.z-dn.net/?f=F%20%3D%20%5Cfrac%7B%5CDelta%20P%7D%7B%5CDelta%20t%7D)
here we have also know that when car hits the bug then force applied by wind shield on the bug is same as the force applied by the bug on the car's wind shield as per Newton's III law
![F_{12} = F_{21}](https://tex.z-dn.net/?f=F_%7B12%7D%20%3D%20F_%7B21%7D)
so we know that
![\frac{\Delta P_{12}}{\Delta t} = \frac{\Delta P_{21}}{\Delta t}](https://tex.z-dn.net/?f=%5Cfrac%7B%5CDelta%20P_%7B12%7D%7D%7B%5CDelta%20t%7D%20%3D%20%5Cfrac%7B%5CDelta%20P_%7B21%7D%7D%7B%5CDelta%20t%7D)
so we have
![\Delta P_{12} = \Delta P_{21}](https://tex.z-dn.net/?f=%5CDelta%20P_%7B12%7D%20%3D%20%5CDelta%20P_%7B21%7D)
so correct answer will be
C. The bug's change in momentum is equal to the car's change in momentum.
Answer: The final temperature is 470K
Explanation: Using the relation;
Q= ΔU +W
Given, n = 2mol
Initial temperature T1= 345K
Heat =Q= 2250J
Workdone=W=-870J(work is done on gas)
T2 =Final temperature =?
ΔU =3/2nR(T2-T1)
ΔU=3/2 × 2 ×8.314 (T2 - 345)
ΔU=24.942(T2-345)
Therefore Q = 24.942(T2-345)+ (-870)
2250=24.942(T2-345)+ (-870)
125.09=(T2-345)
T2 =470K
Therfore the final temperature is 470K