Determine the force necessary to accelerate a mass of 20 lbm at a rate of 60 ft/sec2 vertically upward.

thrust can be approximated by the expression T = An aircraft of mass 240,000kg is powered by a jet engine whereby the horizontal 198 +2t², where T is the thrust in kN and t is the time in seconds. If the aircraft has an initial horizontal velocity of 120ms ¹, determine the new horizontal velocity after 12s.

1. A 25kg boy is riding a merry-go-round with a radius of 5m. What is the centripetal force on the boy if his velocity is 6 m/s?

The heat-transfer rate to the surroundings from a person at rest is about 100 W. Suppose the ventilation system fails in an auditorium containing 2000 people. Assume there is no heat transfer through the auditorium walls. A. Determine the increase in internal energy of the air in the auditorium during the first 20 min after the ventilation system fails. Express your result in MJ. B. Considering the auditorium and all of the people as a system, determine the increase in internal energy (MJ) of the system. How do you explain the fact that the temperature of the air increases?

A body weighing 558 kg accelerates from 55 ft/s to 146 ft/s. Calculate the change in kinetic energy of the object.

Question 7 The large piston of a hydraulic lift has a radius of 20 cm. What force must be applied to the small piston of radius 2.0 cm to raise a car of mass 1500 kg to the same level as shown? F₁ Small piston Large piston A₂ F₂

Consider a disc of mass M with a radius of 0.5 m that is lying on a slope at a 45-degree angle to the horizontal. It grips the hill well and does not slide. The disc is designed in such a way that its mass per unit area, (r), equals r1/2 kg m2, where r is the disc's radial distance in metres from its axis. Calculate the disk's mass.