If the current takes him downstream we must find the resultant vector of the velocities: $V res= \sqrt{1^{2}+0.91^{2} } = \sqrt{1.8281}= 1.3520747$ Then if the river is 3000 m-wide the swimmer will have to pass:
1.3520747 · 300 = 4056.14 m t = 4056.14 m : 1 m/s
a ) It takes 4056.15 seconds ( 1 hour 7 minutes and 36 seconds ) to cross the river.
b ) 0.91 · 3000 = 2730 m
He will be 2730 m downstream.

5 0

4 years ago

Sing the Law of Gravitation, explain why the moon orbits the earth and the planets orbit the sun.

Sladkaya [172]

The gravity of the Sun keeps the planets in their orbits rotating. The same as the Moon orbits the Earth because of the pull of earth's gravity, the earth orbits the Sun because of the pull of the Sun's gravitational pull.

Any questions please feel free to ask. Thanks

8 0

4 years ago

Out of a pair of identical springs of force constants, 240Nm-1 one is compressed by 10 cm and the other is stretched by 10 cm. W

Nadusha1986 [10]

Explanation:

<h3>Answer is zero</h3>

The stored potential energy of a spring is independent whether it is compressed or expanded

This doesn't depend upon movement in left from natural length or right.

This is because the spring always does negative work and opposite to the direction of motion.