Ajet plane lands with a speed of 87 m/s and can accelerate at a maximum rate of −4.10 m/s2 as it comes to rest. (a) from the instant the plane touches the runway, what is the minimum time needed before it can come to rest?

A75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. the motor operates 4368 hours a year at a load factor of 0.75. taking the cost of electricity to be $0.12/kwh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. also, determine the simple payback period if the pu