What is the sector area formula? Now we know that the center angle of the circle is 90 degrees and the length of the generatrix is 4. How can we find the area of this sector?

What is the sector area formula? Now we know that the center angle of the circle is 90 degrees and the length of the generatrix is 4. How can we find the area of this sector?

Generatrix means radius~
S=1/4πr²
=1/4π*4*4
=4π

A physics problem: after a plane returns to the airport, it lands at the speed of 60m / s and taxis at the speed of 6m / S2
A physics problem: after a plane returns to the airport, it lands at the speed of 60m / s and taxis in a straight line with the acceleration of 6m / S2. Calculate the taxiing distance within 4S before the aircraft stops taxiing

In this kind of question, we can turn the uniform deceleration movement into the uniform acceleration movement starting from the rest
So s = 1 / 2at ^ 2 = 1 / 2 * 6 * 4 ^ 2 = 48m
The taxiing distance is 48m within 4S before the aircraft stops taxiing

The landing speed of an aircraft is 216KM / h, and then it decelerates and taxis uniformly. The acceleration is 2m / S2. At least how long does the runway of the airport take for the aircraft to stop safely?

According to the velocity displacement formula v2-v02 = 2aX of uniform speed change linear motion, substituting the data into & nbsp; & nbsp; X = V2 − v022a = 900m, the minimum length of airport runway is 900m