Answer:
his speeds while going to city is 10 mph and while his round trip the speed will be 9 mph
Explanation:
Let say the speed of the bicycle while he moves towards the city is "v"
now the speed of the round trip must be smaller by 1 mph
so its speed for round trip will be

now we know that total time of the motion is 19 hr
so we will have


so we will have




by solving above equation we have

so his speeds while going to city is 10 mph and while his round trip the speed will be 9 mph
Answer:
B. normal force
Explanation:
Because there is no frictional or resistance force. However gravitational force is applied downroad from the center of the cup thus the contact force that is perpendicular to the surface that an object contacts which is the normal force exerted upward from the table that prevents an object from falling.
The free-body diagram of the forces acting on the flag is in the picture in attachment.
We have: the weight, downward, with magnitude

the force of the wind F, acting horizontally, with intensity

and the tension T of the rope. To write the conditions of equilibrium, we must decompose T on both x- and y-axis (x-axis is taken horizontally whil y-axis is taken vertically):


By dividing the second equation by the first one, we get

From which we find

which is the angle of the rope with respect to the horizontal.
By replacing this value into the first equation, we can also find the tension of the rope:
Answer:
θ = 20.9 rad
Explanation:
In a blender after a short period of acceleration the blade is kept at a constant angular velocity, for which we can use the relationship
w = θ / t
θ = w t
if we know the value of the angular velocity we can find the angular position, we must remember that all the angles must be in radians
suppose that the angular velocity is w = 10 rpm, let us reduce to the SI system
w = 10 rpm 
= 1,047 rads
let's calculate
θ = 1,047 20
θ = 20.9 rad
I already answered this quesiton. The fact is that there are only two kind of poles and since the two taped poles of the magnets labeled A and B attracts one to each other, we know that the two taped poles of the first two magnets are oppsosite.
Then, the taped pole of the third magnet has to be equal to one of the first two taped poles and opposite to the other of the first two taped poles.
That drives you to conclude (predict) that when she brings the taped end of the third magnet (magnet C) near each of the first two magntes, in one case they will attract each other and in the other case they will repele mutually.