Answer:
W = 18.88 J
Explanation:
Given that,
Constant force, F = 11.8 N (in +x direction)
Mass of an object, m = 4.7 kg
The object moves from the origin to the point (1.6i – 4.6j) m
We need to find the work is done by the given force during this displacement. The work done by an object is given by the formula as follows :

So, the work done by the given force is 18.88 J.
To reduce friction between two surfaces, you have to
make the surfaces smoother.
The best way to do that is to introduce a fluid between them,
like grease, oil, or air.
If the current takes him downstream we must find the resultant vector of the velocities:

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 mHe will be 2730 m downstream.
Answer:
Change in temperature ∆(tita) is 266.097°C
Explanation:
Ok kinectic energy = 1/2MV²
5.4 grams =( 5.4/1000) kilogram
Kinectic energy =( 1/2 )*(5.4/1000)*261²
Kinectic energy = 183.9267 joules
If kinetic energy = thermal energy
183.9267 joules = mc∆(tita)
Where ∆(tita) = change in temperature
And c = 128 J/kg
∆(tita) = 183.9267/((5.4/1000)*128)
∆(tita) = 266.097
∆(tita) = 266.097°C