The answer is (A) the object must be at rest.
When all of the forces acting on an object balance, the net force is zero and hence the object will not move.
Yes, the direction might also change under some special circumstances.
Scobie will take 10 days to drive around Earth's equator.
To calculate the time that takes Scobie to drive around Earth's equator we need to find the distance, which is given by the equation of a circumference:

<em>Where:</em>
r: is the Earth's radius = 6371 km
Then, the distance is:

Now, if we divide the above distance by the speed of the car we can find the time:

Therefore, Scobie will take 10 days to drive around Earth's equator.
To learn more about distance and time here: brainly.com/question/14236800?referrer=searchResults
I hope it helps you!
V = f x wavelength
V = 5 x 10
V = 50m/s
The experiments that claimed to demonstrate cold fusion were found
to have been faulty by others who reviewed them. Also, nobody else
was
able to reproduce the finding in other laboratories. In the world
of
Science, this pretty much says that the initial claims were unfounded.