Mechanics | Relativity Answers

A steel safe with a mass 800 kg is to be loaded onto a truck 1.00 m above the ground by sliding it up a plank 3.00 m long. If it tales 100 newtons to overcome friction, what total force is necessary to push the safe up the plank?

a 1600kg car driving at 80kmhr^-1 puts the brakes on. if µ =0.68, what's the stopping distance? (deceleration due to brakes =2.9ms^-2)

A body of mass 0.15 kg executes SHM described by the equation
x(t) = 2sin(pt + p/ 4)
where x is in meters and t is in seconds. i) Determine the amplitude and time period
of the oscillation. ii) Calculate the initial values of displacement and velocity.
iii) Calculate the values of time when the energy of the oscillator is purely kinetic

convert 2.4cm/year to km/millions years

An object of density 20 grams per centimetre cube weighs 200 grams when suspended from a spring balance. It is then inserted into a liquid of density 0.6 grams per cm cube until 1/3 of its volume is immersed in the liquid. Calculate the tension in the spring in newton.

a) What should be the angular velocity of the earth such that a person of mass 80 kg
standing on the earth at the equator would actually fly off the earth? (5)
b) A ball of mass 60g is moving due south with a speed of 50 ms−1
at latitude 30ºN.
Calculate the magnitude and direction of the coriolis force on the ball. Compare the
magnitude of this force to the weight of the ball.

Titan, a satellite of Saturn, has a mean orbital radius of 1.22 × 109 m. The orbital period
of Titan is 15.95 days. Hyperion, another satellite of Saturn, orbits at a mean radius of
1.48 × 109 m. Estimate the orbital period of Hyperion.

A wheel 2.0 m in diameter lies in the vertical plane and rotates about its central axis
with a constant angular acceleration of 4.0 rad s−2
. The wheel starts at rest at t = 0 and
the radius vector of a point A on the wheel makes an angle of 60º with the horizontal at
this instant. Calculate the angular speed of the wheel, the angular position of the point A
and the total acceleration at t = 2.0s.

A girl is sitting with her dog at the left end of a boat of length 10.0 m. The mass of the
girl, her dog and the boat are 60.0 kg, 30.0 kg and 100.0 kg respectively. The boat is at
rest in the middle of the lake. Calculate the centre of mass of the system. If the dog
moves to the other end of the boat, the girl staying at the same place, how far and in
what direction does the boat move?