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).
Answer:
Average speed = 1.2 m/s
Average velocity = 0.4 m/s
Explanation:
Average speed = total distance/total time
Average speed = (40 + 20)/(40 + 10)
Average speed = 60/50
Average speed = 1.2 m/s
Average velocity = displacement/time
Now, she ran 40 m south and ran 20 m back north which is in the direction of where she began the journey.
Thus;
Displacement = 40 - 20 = 20 m
Average velocity = 20/50 = 0.4 m/s
Answer
given,
Radius of sphere = 6.38 × 10⁶ m
time = 1 day = 86400 s



a) at equator


v = 464 m/s
acceleration of the person



b) at a latitude of 61.0 ° north of the equator.






acceleration of the person



The electric magnet (Electromagnetic) is temporary because you can turn it on and off. When it's power source is gone, the magnet becomes useless. Usually it's power source is a battery, but it could be solar with a switch. Hope this helps. Please give me brainliest is this helps you.
I believe it was the Greek on astronomy or something close to that that discovered that the world was round.