Answer:
v = 8.65 m/s
Explanation:
Given that,
Distance covered by the doge, d = 45 m
Time taken, t = 5.2 s
We need to find its average speed. The total distance covered divided by the total time taken is called the average speed of an object. So,

So, the average speed is 8.65 m/s.
A projectile fired upward from the Earth's surface will usually slow down, come momentarily to rest, and return to Earth. For a certain initial speed, however it will move upward forever, with its speed gradually decreasing to zero just as its distance from Earth approaches infinity. The initial speed for this case is called escape velocity. You can find the escape velocity v for the Earth or any other planet from which a projectile might be launched using conservation of energy. The projectile of mass m leaves the surface of the body of mass M and radius R with a kinetic energy Ki = mv²/2 and potential energy Ui = -GMm/R. When the projectile reaches infinity, it has zero potential energy and zero kinetic energy since we are seeking the minimum speed for escape. Thus Uf = 0 and Kf = 0. And from conservation of energy,
Ki + Ui = Kf + Uf
mv²/2 -GMm/R = 0
∴ v = √(2GM/R)
This is the expression for escape velocity.
The distance from one crest to the next crest in a set of waves is called the wavelength. The distance from the crest of one wave to the equilibrium point is called frequency.
Hope that helped! =)
Equation 1 :
m1 : m1a =T
Equation 2:m2 : m2a= F - T
Adding 1 and 2a=0.073
Placing in equation 1
we get T = 218.18N
You need to know the speed and direction of object