If you are driving at the speed of 90 km/hour. What is your speed in meter/second

speed = 25 m/s

Step-by-step explanation:

Driving at a speed of 90 km / hour . what is the speed in meters per seconds.

converting from km to meter one have to multiply by 1000. This means 1 km is equal to 1000 meter. Converting 90 km to meter we have to multiply 90 by 1000.

90 × 1000 = 90000 meters

The time is in hours so we have to convert to seconds as required by the question.  

60 minutes = 1 hour

Therefore,

1 minutes = 60 seconds

60 minutes = 3600 seconds

This means 1 hour = 3600 seconds

speed = 90000/3600

speed = 25 m/s

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240