Answer:
39 km/h
Step-by-step explanation:
Velocity is the rate of change of distance in a given direction with time. Mathematically,
Velocity = Displacement/time
Like speed, velocity is measured in Km/h or m/s.
Given that the car travels at 54 km/h for first 20seconds,
since 60 seconds = 1 minute and
60 minutes = 1 h,
20 seconds
= 20/(60 ×60) h
= 1/180 h
In the same vein,
30 seconds
= 30 / (60 ×60) h
= 1/120 h
10 seconds
= 10/(60 ×60) h
= 1/360 h
Hence if the car travels 54 km/h for 10 seconds, the distance covered
= 54 × 1/180
= 3/10 Km
If the car travels 36km/h for next 30seconds, the distance covered
= 36 × 1/120
= 3/10 Km
If the car travels 18km/h for next 10 seconds, the distance covered
= 18 × 1/360
= 1/20 km
Total distance = 3/10 Km + 3/10 Km + 1/20 Km
= 13/20 Km
Total time spent = 20 + 30 + 10
= 60 seconds
= 1/60 h
Average velocity = 13/20 km/ 1/60 h
= 39 Km/h
We'll solve this equation in order to find the score of the 4th test, which we denote with x.
. Solving it we find that x=63. And it is the final answer for this problem.
You'd need to start by finding what 40% of 280 is. To do this, you turn 40% into a decimal which is .40 . Multiply .40 x 280 which is 112. Then subtract that answer from 280 which is 168 baseball cards. Hope this helped :)
It is called a difference of squares because there are two things squared being subtracted. You can recognize it when there are two terms, subtraction between the two of them, and you know the square root of both
The measurement of ABC is 125 degrees.
