**Answer:**

**(a) 2.33 A**

**(b) 15.075 V**

**Explanation:**

From the question,

The total resistance (Rt) = R1+R2 = 3.85+6.47

R(t) = 10.32 ohms.

Applying ohm's law,

V = IR(t)..........equation 1

Where V = Emf of the battery, I = current flowing through the circuit, R(t) = combined resistance of both resistors.

Note: Since both resistors are connected in series, the current flowing through them is the same.

Therefore,

I = V/R(t)............. Equation 2

Given: V = 24 V, R(t) = 10.32 ohms

Substitute these values into equation 2

I = 24/10.32

I = 2.33 A.

Hence the current through R1 = 2.33 A.

V2 = IR2.............. Equation 3

V2 = 2.33(6.47)

V2 = 15.075 V

**Answer:**

The SI unit of length verified globally is meters(m)

**Answer:**

434 Hz

**Explanation:**

According to the Doppler effect, when a source of a wave is moving towards an observer at rest, then the observer will observe an apparent frequency which is higher than the original frequency of the source.

In this situation, Tina is driving towards Rita. Tina is the source of the sound wave (the horn), while RIta is the observer. Since the original frequency of the sound is 400 Hz, Rita will hear a sound with a frequency higher than this value.

The only choice which is higher than 400 Hz is 434 Hz, so this is the frequency that Rita will hear.

For every action there is an equal and opposite reaction." So that applies to a roller coaster, between the ride vehicles and the track. When a ride goes up and down the hill, it creates different forces onto the track.

**Answer:**

10.09 N

**Explanation:**

Analogously to Newton's second law, torque can be defined as:

Here, I is the moment of inertia and is the angular acceleration. We have:

Torque is the vector product of the position vector of the point at which the force is applied by the force vector:

Since the effective lever arm is perpendicular to the force, the angle between them is . The magnitud of this vector product is defined as:

.

Solving for F and replacing the known values: