Answer:
0.9378
Explanation:
Weight (W) of the rider = 100 kg;
since 1 kg = 9.8067 N
100 kg will be = 980.67 N
W = 980.67 N
At the slope of 12%, the angle θ is calculated as:

The drag force D = Wsinθ

where;

A = 0.9 m²
V = 15 m/s
∴
Drag coefficient 


Answer:
The new resistor has resistance of 9Ω.
Explanation:
The effective resistance of three resistance is
.
we know the the circuit with 9V battery has current of 3.6A; therefore,
must be


,
which means


Now, Sally wants to connect another resistor in parallel so that the current becomes 4.6A. The resistance required for that is

.
which means the 4th resistor
must satisfy the equation

and since

equation (2) becomes

which we solve for
:



Thus, the resistance of the new resistor is 9 ohms.
Answer:
μ = 0.385
Explanation:
Given that,
The mass of the student, m = 69 Kg
The horizontal force applied, F = 260 N
The normal force acting on the body, weight = mg = 69g N
= 676.2 N
The coefficient of friction acting on a body is equal to the force acting on the body to the normal force acting on the body due to gravitation.
The formula for coefficient of friction,
μ = F / N
Substituting the values in the above equation,
μ = 260 N / 676.2 N
= 0.385
Hence, the coefficient of friction, μ = 0.385
Answer:
The magnitude of the force on the wire is 2.68 N.
Explanation:
Given that,
Length of the wire, L = 5 m
Magnetic field, B = 0.37 T
Angle between wire and the magnetic field, 
Current in the wire, I = 2.9 A
We need to find the magnitude of the force on the wire. The magnetic force in the wire is given by :

So, the magnitude of the force on the wire is 2.68 N. Hence, this is the required solution.