A 6470 kg helicopter accelerates upward at 0.57 m/s2 while lifting a 1180 kg frame at a construction site (a) What is the lift force exerted by the air on the helicopter rotors? (b) What is the tension in the cable (ignore its mass) that connects the frame to the helicopter? (...
A 800 N crate is being pulled across a level floor by a force F of 320 N at an angle of 29° above the horizontal. The coefficient of kinetic friction between the crate and the floor is 0.25. Find the magnitude of the acceleration of the crate.
A box of books weighing 323 N is shoved across the floor by a force of 477 N exerted downward at an angle of 35° below the horizontal. (a) If μk between the box and the floor is 0.51, how long does it take to move the box 4.80 m starting from rest? (b) What is the max...
Suppose that you are standing on a train accelerating at 0.39g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
An elevator (mass 4125 kg) is to be designed so that the maximum acceleration is 0.0300g. What is the maximum force the motor should exert on the supporting cable? What is the minimum force the motor should exert on the supporting cable?
Two forces are applied to a car in an effort to accelerate it. The first force, F1 = 326 N, is applied at an angle α = 40° to the forward dashed line. The second force, F2 = 488 N, is applied at an angle β = 8° to the forward dashed line. a. What is the resul...
Two planes approach each other head-on. Each has a speed of 765 km/h, and they spot each other when they are initially 11.0 km apart. How much time do the pilots have to take evasive action?
A projectile is shot from the edge of a cliff h = 225 m above ground level with an initial speed of v0 = 155 m/s at an angle of 37.0° with the horizontal a. Determine the time taken by the projectile to hit point P at ground level. b. Determine the range X of the projectil...
A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge 235 m below. Assume the plane is traveling horizontally with a speed of 195 km/h (54.2 m/s). Suppose, instead, that the plane releases the supplies a horizontal distance of 425 m in advance of...
A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge 235 m below. Assume the plane is traveling horizontally with a speed of 195 km/h (54.2 m/s). How far in advance of the recipients (horizontal distance) must the goods be dropped
Can someone please help wright a proof for the following. given: JKLM is a square prove: MK is perpendicular to LJ the figure in front of me is a square labeled JKLM and there are diagonals JL and KM