Answer:
Δt = 0.315s
Explanation:
To calculate the time difference, in which both fans hear the batterstrike, you first calculate the time which takes the sound to travel the distances to both fans:
d1: distance to the first fan = 18.3 m
d2: distance to the second fan = 127 m
vs: speed of sound = 345 m/s
You replace the values of the parameters to calculate t1 and t2:
The difference in time will be:
Hence, the time difference between hearing the sound at the location s of both fans is 0.315s
Answer:
ΔR = 5 s
Explanation:
The absolute uncertainty or error in an expression is
ΔR = | | ΔB + |
| ΔA
the absolute value guarantees to take the unfavorable case, that is, the maximum error.
We look for the derivatives
= 1
= -1
we substitute
ΔR = 1 ΔB + 1 ΔA
of the data
ΔB = 3 s
ΔA = 2 s
ΔR = 3 + 2
ΔR = 5 s
Answer:
F = 24 N
Explanation:
In this exercise we have a bar l = 100 m with a center of gravity x = 4 m, which force is needed to lift it from the other end
Let's use the rotational equilibrium relationship, where we consider the counterclockwise rotations as positive and fix the reference system at the point closest to the center of gravity
∑ τ = 0
F l -x W = 0
F =
let's calculate
F = 4/100 600
F = 24 N