There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:

- radius of the hill:

Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car

(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,

, so we can write:

(1)
By rearranging the equation and substituting the numbers, we find N:

(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:

(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:

from which we find
We don't even need to know how many pulses were produced
in those 3 seconds.
The beginning of the first pulse took 3 seconds to travel
45 centimeters from the generator.
Its speed is (45 cm) / (3 sec) = 15 cm/sec.
A driver have to stop for a school bus when the red lights are flashing and there is no barrier between his/her vehicle and the bus.
<h3>What are traffic rules?</h3>
Traffic rules are rules that are expected to follow by the road users for the safety of everyone using the road.
For instance, when the red lights are flashing , it simply means to stop, while the green light means that the vehicle can continue to move, and yellow light means to be at alert to move.
Read more on traffic rules here:
brainly.com/question/1071840
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