Answer:
a. 13.7 s b. 6913.5 m
Explanation:
a. How much time before being directly overhead should the box be dropped?
Since the box falls under gravity we use the equation
y = ut - 1/2gt² where y = height of plane above ocean = 919 m, u = initial vertical velocity of airplane = 0 m/s, g = acceleration due to gravity = -9.8 m/s² and t = time it takes the airplane to be directly overhead.
So,
y = ut - 1/2gt²
y = 0 × t - 1/2gt²
y = 0 - 1/2gt²
y = - 1/2gt²
t² = -2y/g
t = √(-2y/g)
So, t = √(-2 × 919 m/-9.8 m/s²)
t = √(-1838 m/-9.8 m/s²)
t = √(187.551 m²/s²)
t = 13.69 s
t ≅ 13.7 s
So, the box should be dropped 13.69 s before being directly overhead.
b. What is the horizontal distance between the plane and the victims when the box is dropped?
The horizontal distance x between plane and victims, x = speed of plane × time it takes for box to drop = 505 m/s × 13.69 s = 6913.45 m ≅ 6913.5 m
Answer:
d) v1 = v2 = v3
Explanation:
This can be answered using conservation of energy. We calculate the mechanical energy E=K+U (sum of kinetic and gravitational potential energies) at the original and final points, and impose they are equal.
At the original point we have, for the three balls:
At the final point we have, for the three balls:
Since we have 
, and 
is the same for all balls, then 
is the same for all balls, which means that 
, the final velocity, is the same for all balls.
Answer:
if one wave has a negative displacement, the displacements would be opposite each other, so the displacement where the waves overlap is less than it would be due to either of the waves separately.
-causes a moment where the net displacement of the medium is zero. energy of waves hasn't vanished, but it is in the form of the kinetic energy of the medium
-then both emerge unchanged
Explanation:
Answer:
b Use a balance to determine the mass of the car. Use a motion sensor to measure the speed of the car at a time of 0s and at time of 5s .
Explanation:
The right way to measure the net force on the car is take the measurement of its mass then find the speed of the car within the time 0s to 5s.
This is because the net force acting on car is given as;
Force = mass x acceleration
By using the balance, the mass is determine
Acceleration is the rate of change of velocity with time.
Acceleration = 
v is the final velocity
u is the initial velocity
t is the time taken
Now,
Force = mass x
Thank you for posting your question here at brainly. Below is the solution. I hope it helps.
m=24 kg, Ff=53 N, g=9.8 m/s^2,
use the formula Fg<span> = mg, F</span>g=24*9.8,
solve for Fg, Fg=235.2 N,
then use the formula Ff<span> = ต</span>kFn, 53=235.2ตk,
solve for ตk, ตk<span>=.23</span>
