Distance<-------------300--------------><-------------------x----------------->
⊕---------------------------------⊕--------------------------------------⊕ Express Freight Overtaking point
Speed 55 speed 30
Let x be the distance travelled by Freight until the point of overtaking
Time = Distance/Speed, then:
Time (freight) = Distance (fright)/Speed (freight) And
Time (Express) = Distance (Express)/Speed (Express).
Now plug in the relative number:
Time (freight) = x/30 and Time (express) = (x+300)/55. But note that both times are equal, then:
x/30 = (x+300)/55 OR (x÷30 = (x+300)÷55) [Answer C]
Now let's find the distance x. Cross multiplication;
55x= 30(300+x) →55x = 9,000 + 30x
55x - 30x = 9,000 → 25x = 9,000 and x = 9,000/25 = 360 miles
Time needed for Freight to travel 360 m = 360/30= 12 Hours
Time needed for Express to travel (300+360) m = 660/55= 12 Hours
As you see, it's the same time of 12 hours
Don't forget that Distance = Speed x time or time = Distance/Speed, etc.
Answer:
0.448 seconds
Step-by-step explanation:
d = -16t² -4t + 412
find t when d = 407
substituting d = 407 into the equation:
407 = -16t² -4t + 412 (subtract 407 from both sides)
-16t² -4t + 412 - 407 = 0
-16t² -4t + 5 = 0 (multiply both sides by -1)
16t² + 4t - 5 = 0
solving using your method of choice (i.e completing the square or using the quadratic equation), you will end up with
t = (-1/8) (1 + √21)= -0.70 seconds (not possible because time cannot be negative)
or
t = (-1/8) (1 -√21) = 0.448 seconds (answer)
You cross multiply/butterfly method so 5•6= 30 and 5•8=40 so it would be 30/40 OR 3/4 simplified
Answer:
3 deg C
Step-by-step explanation:
Start with -8 deg and add 11 deg.
-8 + 11 = 3
Answer: 3 deg C
