I would say that this is the first law of thermodynamics.
Answer:
The force of friction that acts on him is

Explanation:
The firefighter with an acceleration of 3m/s^2 take the gravity acceleration as 10m/s^2 isn't necessary to know the coefficient of friction just to know the force of friction:




Sole to Fk



Answer:
Lens at a distance = 7.5 cm
Lens at a distance = 6.86 cm (Approx)
Explanation:
Given:
Object distance u = 12 cm
a) Focal length = 20 cm
b) Focal length = 16 cm
Computation:
a. 1/v = 1/u + 1/f
1/v = 1/20 + 1/12
v = 7.5 cm
Lens at a distance = 7.5 cm
b. 1/v = 1/u + 1/f
1/v = 1/16 + 1/12
v = 6.86 cm (Approx)
Lens at a distance = 6.86 cm (Approx)
Complete Question:
A coin is dropped off of a building landing on its side. It hits with a pressure of 400 N/m². It hits with a force of 0.1N. Calculate the area of the coin?
Answer:
Area = 0.00025 m²
Explanation:
Given the following data;
Pressure = 400N/m²
Force = 0.1N
To find the area of the coin;
Pressure = Force/area
Area = Force/pressure
Substituting into the equation, we have;
Area = 0.1/400
Area = 0.00025 m²