Mechanics | Relativity Answers

A 12.2 m crane weighs 18.0 kN and is lifting a 50.3 kN load. The hoisting cable (tension T1) passes
over a pulley at the top of the crane and attaches to an electric winch in the cab. The pendant cable
(tension T2) which supports the crane, is fixed to the top of the crane. Find the tensions in the two cables.

1. A force of 48.0 N is required to start a 6.0 Kg box moving across a horizontal
concrete floor.
a) What is the coefficient of static friction between box and floor?
b) If the 48.0 N force continues, the box accelerates at 0.70m/s2
, what is the
coefficient of kinetic friction?

Two blocks are free to slide along the frictionless wooden track ABC. The block of mass m1=5.0 kg is released from A which is 5.0 m above the ground. Protruding from its front end is the north pole of a strong magnet, attracting the south pole of an identical magnet embedded in the back end of the block of mass m2 =10.0 kg, initially at rest on the ground. The two blocks touches and start to move at B. Calculate the maximum height at C to which m2m1 rises after the inelastic collision.

. A 2000-kg communication satellite is placed in the geosynchronous orbit around the Earth. Find its speed and altitude. Give the mass of the earth is 5.98x1024kg, the radius of the Earth is 6.38x106
meter.

An airplane flying 60 m/s is accelerated uniformly at the rate of 0.5 . What is the velocity at the end 10 s

A particle is projected at an angle of 60O to the horizontal with a speed of 20 m/s and total time of pacicle flight at 3.46s Calculate of Speed of the particle at its maximum height [take g = 10 m/s2 ]

A 7650 kg helicopter accelerates upward at 0.80m/s2, while lifting a 1250 kg frame at a construction site.
a) What is the lift force exerted by air on the helicopter rotors?
b) What is the tension in the cable (ignore its mass) that connects the frame to the
helicopter?
c) What force does the cable exert on the helicopter?

What does the slope of a distance-time graph represent?
a. Speed
b. Velocity
c. Displacement
d. Acceleration

John slides down a hill on a toboggan. He starts from rest and speeds up to 7.9 m/s in 8.0 s.
Find his acceleration in m/s2
.
a. a. 0.66 m/s2
[downhill]
b. b. 0.77 m/s2
[downhill]
c. c. 0.88 m/s2
[downhill]
d. d. 0.99 m/s2
[downhill]

A cheetah is running at 93km/hr while hunting an animal that is 150 metres away. How long
will it take the cheetah to reach its prey? (Assume uniform motion).
a. 1.6 seconds
b. 2.5 seconds
c. 4.4 seconds
d. 5.8 seconds