A boat, whose speed in still water is 8.0 m/s, crosses a river with a current of 6.0 m/s. If the boat heads perpendicular to the current, what is the speed of the boat relative to an observer standing on the shore as it crosses the river?

A.) 5.3 m/s B.) 8.0 m/s C.) 6.0 m/s D.) 10.0 m/s

D. 10m/s

Given,

speed of boat () = 8.0m/s

speed of river current () = 6.0m/s

Since the boat travels perpendicular to the current;

The resultant speed (v) of the boat, relative to an observer, will be the vector sum of the individual speeds of the boat and the current. i.e

v =  -------------------------(i)

Substitute the values of and into equation (i)

v =  

v =

v =

v = 10m/s

Therefore, the speed of the boat relative to an observer standing on the shore as it crosses the river is 10m/s.

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.