Answer:
3.59 m/s
Explanation:
The average velocity is defined as:
The turtle first walks 18m south, and then is taken 1,1Km (or 1100m) north. Thus, the total displacement is 1082m north (1100m north - 18m south).
Now we have to calculate the total time, which will be equal to the sum of the time the turtle walked and the time it was taken by truck.
The walking time is 3.5 minutes. Since 1 minute = 60 seconds, then the walking time is 210 seconds.
To calculate the truck time we use the equation:
Time = 
Where the distance the truck travelled is 1100m and the speed of the truck is 12m/s.
Thus,
Truck time= 
= 91.67s
The total time is the sum of the walking time and the truck time.
Total time = 210s + 91.67s = 301.67s.
As mencioned previously, the average velocity is equal to total displacement/ total time, thus:
Average velocity = 
= 3.59 m/s North
Since the average velocity is a vector, it has a magnitude and a direction. In this case the magnitude is 3.59 m/s and the direction is north since the turtle's final displacement is north of where it started.
Most of the time the towns get flooded and many people die and lose their homes and their jobs, businesses by the floods and the natural environment is destroyed ,air pollution is produced, the ecosystem could be disrupted and dams are known to fall over and dams are really expensive to build, The dams also cause geological damage, example earthquakes and spills happen.
Answer:
generators
Explanation:
the machine which turns in a power station
Explanation:
Assuming the wall is frictionless, there are four forces acting on the ladder.
Weight pulling down at the center of the ladder (mg).
Reaction force pushing to the left at the wall (Rw).
Reaction force pushing up at the foot of the ladder (Rf).
Friction force pushing to the right at the foot of the ladder (Ff).
(a) Calculate the reaction force at the wall.
Take the sum of the moments about the foot of the ladder.
∑τ = Iα
Rw (3.0 sin 60°) − mg (1.5 cos 60°) = 0
Rw (3.0 sin 60°) = mg (1.5 cos 60°)
Rw = mg / (2 tan 60°)
Rw = (10 kg) (9.8 m/s²) / (2√3)
Rw = 28 N
(b) State the friction at the foot of the ladder.
Take the sum of the forces in the x direction.
∑F = ma
Ff − Rw = 0
Ff = Rw
Ff = 28 N
(c) State the reaction at the foot of the ladder.
Take the sum of the forces in the y direction.
∑F = ma
Rf − mg = 0
Rf = mg
Rf = 98 N
Answer:
16.2 days
Explanation:
Find the number of halflives:
1/2 * 1/2 = 1/4 so <u>two</u> halflives have passed
2 * 8.1 days = 16.2 days
