Answer:
t=1.623 sec
Explanation:
The distance traveled before the echo is had is:

Given the speed of sound as v=345m/s, we use the speed equation to solve for t:

Hence, it takes 1.623 seconds to hear the echo.
Answer:
11 m/s south
Explanation:
The velocity of the passenger relative to the river bank is equal to the velocity of the passenger relative to the ferry, plus the velocity of the ferry relative to the river, plus the velocity of the river relative to the river bank.
v_passenger,bank = v_passenger,ferry + v_ferry,river + v_river,bank
If we take north to be positive and south to be negative:
v = 1.0 m/s + (-10 m/s) + (-2 m/s)
v = -11 m/s
v = 11 m/s south
Answer: T= 715 N
Explanation:
The only external force (neglecting gravity) acting on the swinging mass, is the centripetal force, which. in this case, is represented by the tension in the string, so we can say:
T = mv² / r
At the moment that the mass be released, it wil continue moving in a straight line at the same tangential speed that it had just an instant before, which is the same speed included in the centripetal force expression.
So the kinetic energy will be the following:
K = 1/2 m v² = 15. 0 J
Solving for v², and replacing in the expression for T:
T = 1.9 Kg (3.97)² m²/s² / 0.042 m = 715 N
Type motion examples and subtypes
electromagnetic radiation disturbance propagating through electric and magnetic fields (classical physics) or the motion of photons (modern physics) radio waves, microwaves, infrared, light, ultraviolet, x-rays, gamma rays
Hope this helps and please mark me as brainlest and like:)