3) A 30 kg child slides freely across a "Slip and Slide" on LEVEL GROUND. While the child slides, the force applied to keep them
1 answer:
Answer:
a = 0.1962 m/s^2
Explanation:
The magnitude of kinetic friction exerted is given by
Where, μ_k= coefficient of kinetic friction= 0.02 and N = reaction force = mg
Where m= mass = 30 Kg and, g is acceleration due to gravity =9.81 m/s^2
F_k=0.02×30×9.81 =5.886 N
Now, since, there is no applied force this kinetic friction force will cause acceleration of the child
⇒ ma = F_k
here, a is the acceleration
⇒30a = 5.886
⇒ a = 0.1962 m/s^2
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Answer:
cost of running the furnace during January is $5619.62
Explanation:
given data
runs a day = 13 hours
January days = 31 days
resistance = 7.2 ohm
current = 16.7 A
cost of electricity = $0.10/kWh
to find out
cost of running the furnace during January
solution
first we get her power consumed by furnace that is
Power consumed = ........1
put here value we get
Power consumed =
Power consumed = 38.7347 W
and
Power consumed by furnace in one hour is
Power consumed by furnace in one hour is = Power consumed × 3600
Power consumed by furnace in one hour is = 38.7347 × 3600
Power consumed by furnace in one hour is 139.445kWh
and
Power consumed by furnace in the month of January is
Power consumed by furnace in the month of January = 139.445kWh × 13 hours × 31 days
Power consumed by furnace in the month of January = 56196.335 kWh
so
cost of running the furnace during January is = $0.10/kWh × 56196.335 kWh
cost of running the furnace during January is $5619.62
Answer:
option D
Explanation:
given,
Intensity of sound = 20 dB
distance = 15 m
intensity of sound is increased to = 50 dB
distance between the sound level = ?
Using relation
L₁ = 20 dB L₂ = 50 dB r₁ = 15 m r₂ = ?
r₂ = 0.47 m
r₂ = 47 cm
hence, the correct answer is option D