Answer:
Explanation:
The tidal current flows to the east at 2.0 m/s and the speed of the kayaker is 3.0 m/s.
Let Vector 
is the tidal current velocity as shown in the diagram.
In order to travel straight across the harbor, the vector addition of both the velocities (i.e the resultant velocity, 
must be in the north direction.
Let 
is the speed of the kayaker having angle \theta measured north of east as shown in the figure.
For the resultant velocity in the north direction, the tail of the vector 
and head of the vector must lie on the north-south line.
Now, for this condition, from the triangle OAB
Hence, the kayaker must paddle in the direction of in the north of east direction.
Answer:
U = 56877.4 J
Explanation:
The potential energy of a body is that which it possesses because it is located at a certain height above the surface of the earth and can be calculated using the following formula:
U = mgh Formula (1)
Where:
U is the potential energy in Joules (J)
m is the mass of the body in kilograms (kg)
g is the acceleration due to gravity (m/s²)
h is the height at which the body is found from the surface of the earth in meters (m)
Data
m= 81.4 kg
g= 9.8 m/s²
h = 71.3 m
Potential energy of Sean and the parachute at the top of the tower
We replace data in the formula (1)
U = m*g*h
U = (81.4 kg)*(9.8 m/s²)*(71.3 m)
U = 56877.4 N*m
U = 56877.4 J
M= gpe / gh
G= gpe / mh
H=gpe / mg
