Answer:
b. Friction decreased when he went from pavement to ice and then increased two more times.
Explanation:
Frictional force depends on the normal force of the surface and a friction coefficient.

Since we're talking about the same car, the value of
will remain constant whereas μ will represent the change in the frictional coefficient of the surface. Now we consider the different surfaces, cars will slide in an icy road which means that the frictional coefficient is smaller than the pavement.
After Joshua returns to the pavement road, the resulting frictional force increases and will do so one more time when he reaches the gravel road. Gravel roads have greater frictional coefficients than pavement roads which means the frictional force will increase a second time.
Answer: 2.83 J/mol
Explanation:
Heat of solution, sometimes interchangeably called enthalpy of solution, is said to be the energy released or absorbed when the solute dissolves in the solvent. A solute is that which can dissolve in a solvent, to form a solution
Given
No of moles of CaCl = 7.5 mol
Total energy used = 21.2 J
Heat of solution = q/n where
q = total energy
n = number of moles
Heat of solution = 21.2 / 7.5
Heat of solution = 2.83 J/mol
Answer: The changing magnetic field caused by the material's motion induces a current in the coil of wire proportional to the change in field. If a 0 is represented, the magnetic field does not change between the two domains of a bit, so no current is induced as the magnetic material passes the coil.
Answer: 5 seconds
Explanation:
Given the following :
Inductance (L) = 40 henry
Resistance = 8 ohms
The circuit given above is a Resistor - Inductor (RL) circuit network. The time constant of an RL circuit is the ratio of the circuit Inductance (L) and Resistance (R). Time constant is measured in seconds.
THAT IS;
Time constant = L / R
THEREFORE ;
Time constant = 40 / 8
Time constant = 5 seconds
you would multiply 30 by 15. because its the weight times the distance.