Mechanics | Relativity Answers

The average speed of the International Space Station as it orbits the earth is 7710 m/s. What is this speed in miles per hour? (1 mile = 1.61 km)

e) i) Show that only odd harmonics can be generated in a closed-end organ pipe.
ii) For gravity waves, the phase velocity is given by
vp = Cl1/ 2
Show that group velocity for these waves is half of their phase velocity.

A ball of mass m and radius R rotates with an angular velocity ω_0 about a horizontal axis. If it is placed on a horizontal plane, the coefficient of friction being µ, how far can the ball travel before it is engaged in a pure rolling motion ?

The small spherical balls are free to move on the inner surface of the rotating spherical chamber of radius R=2.0m. Sphere is rotating about the axes X-X' with angular velocity ω. If the balls reach a steady state at an angular position ϴ=45°, the angular speed ω of device is

2m/s to 6m/s in 2seconds

A ball is kicked with an initial velocity of 14 m/s in the horizontal direction and 21 m/s in the vertical direction. (Assume the ball is kicked from the ground.)
(a)
At what speed (in m/s) does the ball hit the ground?

18

Incorrect: Your answer is incorrect.
m/s
(b)
For how long (in s) does the ball remain in the air?

s
(c)
What maximum height (in m) is attained by the ball?

m

In World War II, there were several reported cases of
airmen who jumped from their flaming airplanes with no
parachute to escape certain death. Some fell about 20,000
feet (6000 m), and some of them survived, with few lifethreatening
injuries. For these lucky pilots, the tree branches
and snow drifts on the ground allowed their deceleration to be
relatively small. If we assume that a pilot’s speed upon impact
was 123 mph (54 m/s), then what was his deceleration?
Assume that the trees and snow stopped him over a distance
of 3.0 m.

What is the effective weight of a person of mass 60 kg carried vertically up in a
rocket with an acceleration of 2g? Draw a properly labelled free-body diagram.
b) An aeroplane flies due east along the equator with a speed of 300 ms−1. Determine the
magnitude and direction of the Coriolis acceleration.

A horizontal disk is rotating counter-clockwise about its axis of symmetry at 14 rps. Its
rotational inertia with respect to its axis of symmetry is 8 kg m2. A second disk, of
rotational inertia 2 kg m2 with respect to its axis of symmetry, rotating clockwise about
the same axis at 7 rps, is dropped on top of the first disk. The two disks stick together
and rotate as one about their common axis of symmetry. What is the angular velocity of
the system?

A fisherman in a boat catches a huge fish with a rod and starts to pull it in. The fish
struggles for a while and then becomes still when it is at a distance of 200 m from the
boat. During this operation, the boat (initially at rest) moves 25 m in the direction of the
fish. If the mass of the boat is 5000 kg, calculate the mass of the fish. Assume that water
exerts no friction