Answer: a) 7.1 * 10^3 N; b) -880 N directed out of the curve.
Explanation: In order to solve this problem we have to use the Newton laws, then we have the following:
Pcos 15°-N=0
Psin15°-f= m*ac
from the first we obtain N, the normal force
N=750Kg*9.8* cos (15°)= 7.1 *10^3 N
Then to calculate the frictional force (f) we can use the second equation
f=P sin (15°) -m*ac where ac is the centripetal acceletarion which is equal to v^2/r
f= 750 *9.8 sin(15°)-750*(85*1000/3600)^2/150= -880 N
Answer:
The velocity is 
Henrietta is at distance
from the under the window
Explanation:
From the question we are told that
The speed of Henrietta is 
The height of the window from the ground is 
Generally the time taken for the lunch to reach the ground assuming it fell directly under the window is

=>
=>
Generally the time taken for the lunch to reach Henrietta is mathematically represented as

Here
is the time duration that elapsed after Henrietta has passed below the window the value is given as 4 s
Now
=>
Generally the distance covered by Henrietta before catching her lunch is

=> 
=> 
Generally the speed with which Bruce threw her lunch is mathematically represented as


Answer: a) Observation
b) observation
c) observation
d) observation
e) inference
f) inference
g) inference
h) inference
Explanation:
observation: The photosphere is made mostly of hydrogen and helium,The photosphere emits mostly visible light,The corona is hotter than the photosphere, The Sun emits neurtrinos
inferences: The Sun generates energy by fusing hydrogen into helium,The core temperature is 10 million k, The convection zone is cooler than the radiation zone,The composition of the photosphere is the same as that the gas cloud that have birth to our solar system.
Answer:
a. If c = 20 cm, then the mass of the brain is m = 5 g.
b. At c = 20 cm, the brain's mass is increasing at a rate of 15.75 g/cm.
Explanation:
From the equation

we have
a. for c = 20 cm

then the mass is m(20) = 5 g.
b. In order to find the rate of change, first we derivate

Evaluated at c = 20 cm, we have

So, at c = 20 cm, the mass of the brain is increasing at a rate of 15.75 g/cm.
Answer:
(a) ε = 1373.8.
(b) The wingtip which is at higher potential.
Explanation:
(a) Finding the potential difference between the airplane wingtips.
Given the parameters
wingspan of the plane is = 18.0m
speed of the plane in north direction is = 70.0m/s
magnetic field of the earth is = 1.20μT
The potential difference is given as:
ε = Blv
where ε = potential difference of wingtips
B = magnetic field of earth
l = wingspan of airplane
v = speed of airplane
ε = 1.2 x 18.0 x 63.6
ε = 1373.8
(b) Which wingtip is at higher potential?
The wingtip which is at higher potential.