Answer:
f ’= 97.0 Hz
Explanation:
This is an exercise of the doppler effect use the frequency change due to the relative movement of the fort and the observer
in this case the source is the police cases that go to vs = 160 km / h
and the observer is vo = 120 km / h
the relationship of the doppler effect is
f ’= f₀ (v + v₀ / v- 
)
let's reduce the magnitude to the SI system
v_{s} = 160 km / h (1000 m / 1km) (1h / 3600s) = 44.44 m / s
v₀ = 120 km / h (1000m / 1km) (1h / 3600s) = 33.33 m / s
we substitute in the equation of the Doppler effect
f ‘= 100 (330+ 33.33 / 330-44.44)
f ’= 97.0 Hz
First we gotta use an equation of motion:
Our vertical distance d= 100 m, initial vertical speed u = 0 m/s (because velocity is fully horizontal), and vertical acceleration a = 9.8 m/s2 because of gravity. Let's plug it all in!
Now we just need to solve for t:
Hit the calculators, and you'll get 4.5 seconds!
I think in parallel circuits.
Answer:
Horizontal distance=?m
Explanation:
Horizontal velocity,u=482ms⁻¹
Height of the cliff=17.7m
Horizontal distance,R=?
R=v×√2h/g
Answer:
Her angular speed (in rev/s) when her arms and one leg open outward is 
Explanation:
Initial moment of inertia when arms and legs in is 
Final moment of inertia when her arms and on leg open outward, 
Initial angular speed 
Let the final angular speed be 
Since external torque on her is zero so we can apply conservation of angular momentum
=>
=>
Thus her angular speed (in rev/s) when her arms and one leg open outward is
