I would think force. Because friction has to have force to work ^-^
Answer:
28.23 years
Explanation:
I = 1100 A
L = 230 km = 230, 000 m
diameter = 2 cm
radius, r = 1 cm = 0.01 m
Area, A = 3.14 x 0.01 x 0.01 = 3.14 x 10^-4 m^2
n = 8.5 x 10^28 per cubic metre
Use the relation
I = n e A vd
vd = I / n e A
vd = 1100 / (8.5 x 10^28 x 1.6 x 10^-19 x 3.14 x 10^-4)
vd = 2.58 x 10^-4 m/s
Let time taken is t.
Distance = velocity x time
t = distance / velocity = L / vd
t = 230000 / (2.58 x 10^-4) = 8.91 x 10^8 second
t = 28.23 years
Answer:
-1.43 m/s relative to the shore
Explanation:
Total momentum must be conserved before and after the run. Since they were both stationary before, their total speed, and momentum, is 0, so is the total momentum after the run off:
where 
are the mass of the swimmer and raft, respectively. 
are the velocities of the swimmer and the raft after the run, respectively. We can solve for 
So the recoil velocity that the raft would have is -1.43 m/s after the swimmer runs off, relative to the shore
Answer:
5 Km/h
Explanation:
From the question given above, the following data were obtained:
Distance travelled = 10 Km
Time = 2 hours
Speed =?
Speed is simply defined as the distance travelled per unit time. Mathematically, it can be represented as:
Speed = distance travelled /time.
With the above formula, we can obtain the speed at which the duck is travelling as follow:
Distance travelled = 10 Km
Time = 2 hours
Speed =?
Speed = distance travelled /time.
Speed = 10 / 2
Speed = 5 Km/h
Thus, the duck is travelling at a speed of 5 Km/h
