I think the answer may be the letter B
Answer: -3.49 m/s (to the south)
Explanation:
This problem can be solved by the Conservation of Momentum principle which establishes the initial momentum
must be equal to the final momentum
, and taking into account this is aninelastic collision:
Before the collision:
(1)
After the collision:
(2)
Where:
is the mass of the car
is the velocity of the car, directed to the north
is the mass of the truck
is the velocity of the truck, directed to the south
is the final velocity of both the car and the truck
(3)
(4)
Isolating
:
(5)
(6)
Finally:
The negative sign indicates the direction of the velocity is to the south
Here current is flowing through the copper wire so this shows that copper is good conductor of electricity.
It is having less resistance as it conducts the current easily
Now a rubber coating on it will protect us from electric shock
So this property shows that rubber is a bad conductor of electricity
It is having large electrical resistance due to which it will conduct no current
Rubber : - No transmittance of electricity
copper :- good transmittance of electricity
Answer:
0,00123 = 1,2*10^{-3}
Explanation:
To write down correctly the number 0,00123 in scientific notation, you take into account that the scientific notation demands that there in only one number after the comma ( , ). Furthermore, it is necessary that you move the comma to the right of the first number different of zero, in this case the number 1. To do this you move the comma three positions.
Then, you have to multiply the expresion 1.23 by 10 with an exponential -3 (because of the movement of the comma in three positions). That is:
0,00123 = 1,23*10^{-3}
But it is mandatory that nly one number can stay after the comma, so, you approximate the number three. In this case, the number is lower than 5, hence, you approximate 3 to 0.
Finally, you have:
0,00123 = 1,2*10^{-3}