We know that the average speed is simply the ratio of the
total distance travelled over the total duration of the trip.
total distance = 500 mi + 380 mi + 600 mi
total distance = 1,480 mi
total time = 10 h + 8 h + 15 h
total time = 33 h
So the average speed is therefore:
average speed = 1,480 mi / 33 h
<span>average speed = 44.85 mi / h</span>
Answer:
the tension in the string an instant before it broke = 34 N
Explanation:
Given that :
mass of the ball m = 300 g = 0.300 kg
length of the string r = 70 cm = 0.7 m
At highest point, law of conservation of energy can be expressed as :


The tension in the string is:

Thus, the tension in the string an instant before it broke = 34 N
Answer:
After 4 s of passing through the intersection, the train travels with 57.6 m/s
Solution:
As per the question:
Suppose the distance to the south of the crossing watching the east bound train be x = 70 m
Also, the east bound travels as a function of time and can be given as:
y(t) = 60t
Now,
To calculate the speed, z(t) of the train as it passes through the intersection:
Since, the road cross at right angles, thus by Pythagoras theorem:


Now, differentiate the above eqn w.r.t 't':


For t = 4 s:
