Answer:
a
Solid Wire 
Stranded Wire 
b
Solid Wire 
Stranded Wire 
Explanation:
Considering the first question
From the question we are told that
The radius of the first wire is 
The radius of each strand is 
The current density in both wires is 
Considering the first wire
The cross-sectional area of the first wire is
= > 
= > 
Generally the current in the first wire is
=> 
=>
Considering the second wire wire
The cross-sectional area of the second wire is
=> 
=> 
Generally the current is
=> 
=>
Considering question two
From the question we are told that
Resistivity is 
The length of each wire is 
Generally the resistance of the first wire is mathematically represented as
=> 
=>
Generally the resistance of the first wire is mathematically represented as
=> 
=>
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. The gas is formed in the reaction is Carbon dioxide. 
is formed.
The change which happened in this reaction is a chemical change.
Since, in chemical change we can't bring a substance to it's actual form how it was in earlier.
Examples: burning of paper is chemical, since we can't get the fine paper again after it is burnt.
Thus, the above reaction is also a chemical change, since we can't get back the lemon juice how it was earlier.
Answer:
Only a backward force is acting, no forward force.
Explanation:
- Once released from the initial push, in absence of friction, the shopping cart would continue moving forward at a constant speed forever.
- As it would move at a constant speed, no net force would be acting on it.
- So, if it is gradually slowing, there must be a net force producing an acceleration in a direction opposite to the movement.
- This force is the kinetic friction force, and is the only force acting on the cart in the horizontal direction.
- As any friction force, opposes to the relative movement between the cart and the horizontal floor, which means that is directed backward.
- This is consistent with the direction of the acceleration of the cart.
Acceleration is found if we have the force and mass.
With the following equation: F = ma, we can find the missing values.
F = 25n
M = 0.5 kg
a = ?
a = f/m
a = 25/0.5
a = 50
a = 50 m/s
So, the acceleration is 50 m/s^2
We can solve the problem by using Newton's second law of motion:
where
F is the net force applied to the object
m is the object's mass
a is the acceleration of the object
In this problem, the force applied to the car is F=1050 N, while the mass of the car is m=760 kg. Therefore, we can rearrange the equation and put these numbers in, in order to find the acceleration of the car:
The equation also tells us that the acceleration and the force have same directions: therefore, since the force exerted on the car is horizontal, the correct answer is
<span>
B) 1.4 m/s2 horizontally.</span>
