(a) 1800 N
The equation of the forces along the vertical direction is:

where
is the component of the applied force along the vertical direction
N is the normal force on the sled
mg is the weight of the sled
Substituting:
F = 1210 N
m = 246 kg

We find N:

(b) 0.580
The equation of the forces along the horizontal direction is:

where
is the horizontal component of the push applied by the mule
is the static frictional force
Substituting:
F = 1210 N
N = 1800 N

We find
, the coefficient of static friction:

(c) 522 N
In this case, the force exerted by the mule is

So now the equation of the forces along the horizontal direction can be written as

where

and
is the new frictional force, which is different from part (b) (because the value of the force of friction ranges from zero to the maximum value
, depending on how much force is applied in the opposite direction)
Solving the equation,

Transformation 3 should Tracy removed from the list. Chemical energy transforms into gravitational potential energy.
<h3> What is the law of conservation of energy?</h3>
According to the Law of Conservation of Energy, energy can neither be created nor destroyed, but it can be transferred from one form to another.
The total energy is the sum of all the energies present in the system. The potential energy in a system is due to its position in the system.
Transformations that occur as an engine runs to power a car is;
1. Chemical energy of fuel transforms into thermal energy.
2. Thermal energy transforms into electrical energy used to lighten the bulb in a car.
3. Thermal energy transforms into kinetic energy to help to run the car.
Chemical energy transforms into gravitational potential energy is the incorrect energy transformation.
Hence, transformation 3 should Tracy removed from the list.
To learn more about the law of conservation of energy, refer to brainly.com/question/2137260.
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(a) 
First of all, we need to calculate the acceleration of the person, by using the following SUVAT equation:

where
v = 0 is the final velocity
u = 20.0 m/s is the initial velocity
a is the acceleration
d = 1.00 cm = 0.01 m is the displacement of the person
Solving for a,

And the average force on the person is given by

with m = 75.0 kg being the mass of the person. Substituting,

where the negative sign means the force is opposite to the direction of motion of the person.
b) 
In this case,
v = 0 is the final velocity
u = 20.0 m/s is the initial velocity
a is the acceleration
d = 15.00 cm = 0.15 m is the displacement of the person with the air bag
So the acceleration is

So the average force on the person is

Explanation:
Derived quantities are quantities dependent on fundamental quantities while derived units are the units of these quantities
Answer:
D. When the temperature of the gas is the same throughout
Explanation: