an athlete runs 5.4 laps around a circular track that is 400.0 m long. If this takes 540 s, what is the average velocity of the
1 answer:
Answer:
Average velocity is 0.296 m/s.
Average speed is 4.0 m/s.
Explanation:
Given:
Distance of the circular track is,
Number of laps ran is,
Time taken for the run is,
Now, total distance covered in 5.4 laps =
Also, since the path is a circle, the final position of the athlete after 5.4 laps will be 0.4 of 400 m ahead of the starting point.
Distance covered in 0.4 laps is,
Therefore, the displacement of the athlete will be 160 m as the athlete is 160 m ahead of the starting point and displacement depends on the initial and final points only.
Now, average velocity is given as:
Average speed is the ratio of total distance covered to total time taken.
So, average speed =
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Answer:
4.15 m/s
Explanation:
As the total energy must be conserved (neglecting air resistance) the change in gravitational potential energy, must be equal to the change in kinetic energy:
ΔE = ΔK + ΔU =0
If we take as a zero reference level for the gravitational potential energy, the height of the swing seat above the ground, (which is equal to 0.21 m), we can find the initial gravitational energy, considering the height of the point where the seat is released, regarding this point:
h₀ = 1.09 m -0.21 m = 0.88 m
⇒ U₀ = m*g*h₀ = 400 N*0.88 m = 352 J
As Uf = 0, ΔU = Uf -U₀ = -352 J
As the swing starts from rest, K₀=0, so we can say:
ΔK = Kf = (1)
As ΔK = -ΔU ⇒ ΔK = 352 J (2)
From (1) and (2) we can solve for vf, as follows:
So, when the swing passes through its lowest position, Betty moves at 4.15 m/s.
Answer: Heat current through the insulator=196W
Electric power= 196W
Explanation: Given: Kglass = 0.040W/m
Temperature of inside glassTi=175°C
Temperature of outside glass To= 35°C
Area=1.4m^2 , L= 4×10^-2
Heat current(H)= K ×A× (Ti - To)/L
Substituting the values into the equation
H = 0.04 × K × 1.4 ×(175-35)/4×10^-2
H= 196W.
The electric power = Heat current =196W
The electric power is the magnitude of heat current
Answer:
f = 2858.33 Hz
Explanation:
given,
distance between speaker (A) and the person = 2.34 m
Distance between speaker (B) and the person is AB =
=
= 2.46 m
path difference d = BP - AP
= 2.46 - 2.34 m
= 0.12 m
now, λ = 0.12
speed of sound = 343 m/s
f = 2858.33 Hz
the lowest frequency that will produce constructive interference is equal to
f = 2858.33 Hz
Horizontal speed = 24.0 m/s
height of the cliff = 51.0 m
For the initial vertical speed will are considering the vertical component. Therefore,
Since the student fires the canonical ball at the maximum height of 51 m, the initial vertical velocity will be zero. This means
let's find how long the ball remained in the air.
Finally, let's find the how far from the base of the building the ball landed(horizontal distance)