Note: <em>The question states the time to go upstream is a number of times (not explicitly written) the time to go downstream. We'll assume a general number N</em>
Answer:

Explanation:
<u>Relative Speed</u>
If a boat is going upstream against the water current, the true speed of motion is
, being
the speed of the boat and
the speed of the water. If the boat is going downstream, the true speed becomes
.
The question states the time to go upstream is a number of times N (not explicitly written) the time to go downstream. The speed of an object is computed as

Where x is the distance traveled and t the time taken for that. The time can be computed by

If
is the time for the upstream travel and
is the time for the downstream travel, then

Siince the same distance x= 10 miles is traveled in both cases:

Simplifying and rearrangling

Operating

Solving for 



If N=3

We can use the required value of N to compute the speed of the boat as explained
Answer:
7572 m/s
Explanation:
The force between two masses separated by a distance r is given as:

Where F is the attractive force between 2 masses, m1 and m2, r is the distance between the centres of the masses and G is the universal gravitation constant, which is 
The mass of the earth (
) is far greater than the mass of the sputnik (
). Therefore
. The mass of the sputnik is neglected, therefore:

But F is actually centripetal acceleration, a = v²/r

Answer:
Gas !
Explanation:
Check to see if you have gas in the tank !
Answer:

Explanation:
As we know that moment of force is given as

now we have


now from above formula we have

here we know that

so we have

