Mechanics | Relativity Answers

A cannon mounted on a pirate ship fires a cannonball at 125 m/s horizontally, at a height of 17.5 m above the ocean surface. Ignore air resistance. (a) How much time elapses until it splashes into the water? (b) How far from the ship does it land?

Average speed equals distance divided by time. On a journey to the Alpha Centauri star system, a space probe travels a distance of 4.12×10[sup]16[/sup] meters in 1.73×10[sup]10[/sup] seconds. (a) Find its average speed in meters per second. (b) How long did the journey take in years? Use 365.24 days per year

Proof with sample calculations and discussion of theory:
An object of mass X, on a pendular arm, will reach the bottom of the swing at the same time as a similar object dropped next to it from the same height.

A person travels by car from one city to another. She drives for 28.4 min @ 67.2 km/h, 12.3 min. @ 117km/h, 38.7 min @ 36.2km/h and spends 15.1 min along the way eating lunch and buying gas. Determine the distance between the cities along the route. Ans in km

A watermelon cannon fires a watermelon vertically up into the air at a velocity of +11.0 m/s, starting from an initial position 1.20 meters above the ground. When the watermelon reaches the peak of its flight, what is its height above the ground?

It takes a shark 3 Seconds to accelerate at a rate of 4.3m/s2 To reach a final speed of 15.0 What was the sharks initial speed?

A 6 kg cart is pulled on a level surface at a constant velocity of 2 m/sec by a constant force of 10 N. What is the acceleration? What is the frictional force opposing the motion?

A container is filled with water to a depth of
47.3 cm. On top of the water floats a 46.2 cm
thick layer of oil with a density of 503 kg/m3.
What is the absolute pressure at the surface
of the water? The acceleration of gravity is
9.81 m/s2 .
Answer in units of Pa.

A 4.9 kg rectangular air mattress is 2.7 m
long, 1.16 m wide, and 0.183 m thick.
What mass can it support in water before
sinking?
Answer in units of kg.

A hollow brass tube has outer diameter D =
3.1 cm. The tube is sealed at one end and
loaded with lead shot to give it a total mass
of M = 88 g. The tube floats in water (of
density 1 g/cm3) in vertical position, loaded
end down.
What is the depth of the bottom end of the
tube?
Answer in units of cm.