Answer:
a) v = 34.5 mph, b) v = 50 mph
Explanation:
The average speed is defined.
v = (x₂ -x₁) / (t₂ -t₁)
If the movement is with uniform speed we can also obtain the average speed, averaging the speeds with a time weight factor, if the time is equal for each speed
v = (v₁ + v₂) / 2
a) For the outward journey
v = (69.0 +0) / 2
v = 34.5 mph
b) For the return trip
v = (69.0 + 31.0) / 2
v = 50 mph
Answer:
She is measuring her speed
Explanation:
Speed is defined as the ratio between the distance covered divided by the time taken to cover that distance:
where
d is the distance covered
t is the time taken
Since Mary is measuring how far she can run in a given period of time, she is measuring the distance she can travel (d) in a given time (t), so she is measuring her speed.
The mass of an object is the amount of substance it is made up of or it contains but the weight of that object is the force exerted by that object as a result of gravity.The S.I. unit for mass is kilograms but weight is measured in Newtons. Mass is constant or does not change but weight depends on the gravity of the place.
There is too much information given, it's hard to understand exactly which variables are important in this problem.
The statement that best describes an external circuit is "<span>D. The flow of an alternating current switches direction when a generator's terminals change its charge." The main difference between direct and alternating current is the direction of flow. Direct current follows only one direction from negatve to positive, while alternating current changes direction periodically.</span>