The power, P (watts) , of a car engine is proportional to the square of its speed, s ( m / s ) . When s = 35 , P = 1580 . Work out the power (to 1 DP) when the speed is 30 m / s

Respuesta :

Answer:

P=2200 , K=35

Step-by-step explanation:

The power, P (watts), of a car engine is proportional to the square of its speed, k%28m%2Fs%29; it means if you have two different powers and speeds, you will have a proportion

P%3Ak%5E2=P%5B1%5D%3Ak%5B1%5D%5E2 or

P%2Fk%5E2=P%5B1%5D%2Fk%5B1%5D%5E2

When given:

k=35, P=2200

Work out the power P%5B1%5D (to 1DP) when the speed is k%5B1%5D=40%28m%2Fs%29

so,

P=2200

 

k=35

k%5B1%5D=40

and you need P%5B1%5D

2200%2F35%5E2=P%5B1%5D%2F40%5E2

2200%2F1225=P%5B1%5D%2F1600

1.79592=P%5B1%5D%2F1600

1.79592%2A1600=P%5B1%5D

P%5B1%5D=2873.5 watts

If the speed is 30 m per second. Then the power of the car engine will be 1160.8 watts.

What is proportion?

A proportionate expression is one in which two items are equal.

The power, P (watts), of a car engine is proportional to the square of its speed s (m/s).

P ∝ s²

P = ks²

We have

s = 35

P = 1580

Then the value of k will be

1580 = (35)² × k

k = 1.2897

Then the equation will be

P = 1.2897s²

If the speed is 30 m per second. Then the power of the car engine will be

P = 1.2897 x 30²

P = 1160.8 watts

More about the proportion link is given below.

https://brainly.com/question/14335762

#SPJ2