Observational studies are a prime example. Observational data is more reflective of the real environments that scientists make their inferences to than controlled experiments. The disadvantage of observational studies is that the variability is far greater. <span />
Answer:
I chose c because it is the greater slope at point c
Answer:
Toward the north, 300 N
Explanation:
Consider the upward direction as positive and downward direction as negative.
Given:
Mass of the balloon is, 
Lift force on the balloon in the upward direction is, 
Take acceleration due to gravity as 10 N/kg.
Now, weight of the balloon acting downward is given as the product of its mass and acceleration due to gravity. Therefore,
Weight is, 
Now, net force is given as the vector sum of both the forces.
The upward direction is the direction of North. So, the net force acting on the balloon is 300 N towards North.
Answer:
F= 4788 N
Explanation:
Because the car moves with uniformly accelerated movement we apply the following formula:
vf²=v₀²+2*a*d Formula (1)
Where:
d:displacement in meters (m)
v₀: initial speed in m/s
vf: final speed in m/s
a: acceleration in m/s²
Data
d=36.9 m
v₀=14.0 m/s m/s
vf= 0
Calculating of the acceleration of the car
We replace dta in the formula (1)
vf²=v₀²+2*a*d
(0)²=(14)²+2*a*(36.9)
-(14)²= (73.8) *a
a= - (196) / (73.8)
a= - 2.66 m/s²
Newton's second law of the car in direction horizontal (x):
∑Fx = m*ax Formula (2)
∑F : algebraic sum of the forces in direction x-axis (N)
m : mass (kg)
a : acceleration (m/s²)
Data
m=1800 Fkg
a= - 2.66 m/s²
Magnitude of the horizontal net force (F) that is required to bring the car to a halt in a distance of 36.9 m :
We replace data in the formula (2)
-F= (1800 kg) * ( -2.66 m/s²
)
F= 4788 N
