Answer:
5km/h
Explanation:
The equation for average speed is
Vavg = Δd/Δt
where Δd is distance and Δt is time
from what's given, we know she travelled 15km in total and the trip took 3 hours in total. We can now plug in the values into the equation
Vavg = 15/3
Vavg = 5km/h
Answer:
The low points are called troughs
I believe the government should encourage both children(society) do not know much about either because they are not taught enough about that subject/topic.
Answer:
A) a frictional force is acting on it
Explanation:
The crate is sliding down the inclined ramp at constant velocity: constant velocity means zero acceleration, a = 0. According to Newton's second law:
F = ma
this also means that the net force acting along the direction of the slope is zero.
Without frictional force, there would be only one force acting along this direction: the component of the weight of the crane parallel to the slope, acting downward:
where 
is the angle of the incline. Therefore, the net force along this direction would not be zero. In order to have a net force of zero, there must be another force acting upward on the crate: and the only force that is possibly acting on the crate against its direction of motion is the frictional force, whose magnitude must be equal to 
, in order to produce a net force of zero (and therefore, a zero acceleration).
