Sry i was knowing the answer i forgot ;(
Answer: When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common physical demonstration of the Doppler effect.
Explanation:
Force=mass x acceleration
f= 0.5 x40
f=20N
Gravity is the correct answer.
Answer:
Part a)

Part b)

Explanation:
Diameter of the circle = 24 ft
Diameter = 731.52 cm = 7.3152 m
now the horse complete 144 trips in one hour
so time to complete one trip is given as


now the speed of the horse is given as



Part a)
Now we know that the power is defined as rate of work done
it is given as




Part b)
Work done to climb up to 3 m height is given by

now we have




now we know that 1 HP = 746 Watt
so we have
