So impulse is a change in momentum.
Mass*(final velocity - initial velocity)
I dont think you will be able to find the average force with the given info because you need to know the time it takes for the car to slow down.
Answer:
Part A: 16.1 V
Part B: 20.5 V
Part C: 21.5%
Explanation:
The voltmeter is in parallel with the 4.5-kΩ resistor and the combination is in series with the 6.5-kΩ resistor. The equivalent resistance of the parallel combination is given as


Part A
The voltmeter reading is the potential difference across the parallel combination. This is found by using the voltage-divider rule.

Part B
Without the voltmeter, the potential difference across the 4.5-kΩ resistor is found using the same rule as above:

Part C
The error in % is given by

Answer:
The new radius of the trajectory of the particle is four times the previous radius
Explanation:
In order to know what is the radius of the trajectory of the charged particle, if its speed is four times as fast, you take into account the following formula, which describes the radius of a charged particle in a magnetic field:
(1)
If the speed of the particle is for time as fast, that is, v' = 4v, you obtain, in the equation (1):

The new radius of the trajectory of the particle is four times the previous radius