Answer:
The force will have to increase
Explanation:
Since Juan has upgraded from a sports car to a large truck, based on Newton's second law of motion, the force needed to keep the truck going at the same speed will have to increase.
According to Newton's second law "the force on an object is equal to the product of its mass and acceleration".
Force = mass x acceleration
A truck has a larger mass compared to a sports car.
By virtue of this, to make sure both automobiles attain the same speed, the force powering them to accelerate must be the same.
Therefore, the force from the engine must increase.
Answer:
resistor R₂ has the lowest current density
Explanation:
The current density is
j = I / A
now let's analyze each case
a) R₂ has an area 2A₀ and a length L₀ that R₁
b) R₃ has an area Ao and a length 3L₀ what R₁
we can see that all the area is given in relation to the resistance R₁
the current density in R₁ is
j₁ = I / A₀
the current density in R₂
j₂ = I / 2A₀
j₂ 2 = ½ I/A₀
the current density in R₃
j₃ = I / A₀
j₂ < j₁ = j₃
therefore resistor R₂ has the lowest current density
