Answer:
16200 km/s
270 km/min
4.5 km/h
Explanation:
Acceleration Formula: Average Acceleration = Δv/Δt (change in velocity over change in time)
Simply plug in our known variables and solve:
a = (45.0 - 0)/10
a = 45.0/10
a = 4.5 km/h
The cheetah's speed is 100x and
The gazelle's speed is 80x + 70.
Set the two equations equal to each other:
100x = 80x +70 (then subtract 80x from both sides).
20x = 70 (then divide by 20).
X =3.5.
The cheetah catches the gazelle after 3.5
As we know that gravitational potential energy is given by

here we have
m = mass = 120 kg

h = height = 8.2 m
now from above formula


so above is the gravitational potential energy of the couch
Note: I'm not sure what do you mean by "weight 0.05 kg/L". I assume it means the mass per unit of length, so it should be "0.05 kg/m".
Solution:
The fundamental frequency in a standing wave is given by

where L is the length of the string, T the tension and m its mass. If we plug the data of the problem into the equation, we find

The wavelength of the standing wave is instead twice the length of the string:

So the speed of the wave is

And the time the pulse takes to reach the shop is the distance covered divided by the speed: