Mechanics | Relativity Answers

The first divers used metal ‘diving bells’ to move air under the water surface.

(a) Modelling the air in bell as a hemisphere with diameter of 2.5 metres, use the following information to calculate the upthrust produced due to the water.

Ρwater= 997 kgm^-3

Volume of a sphere = 4/3𝜋r³

g = 9.81 ms^-2

(b) If the bell was fully submerged and then its suspension cable was released, what would its maximum acceleration be, given that its mass was 4500 kg?

Can you show me how did you arrive at the answer?

A model car is moving around a circular track of radius 3.0 m at a speed of 1.5 m s⁻¹ as shown in the figure. It takes the car 12.6 s to complete one full lap.

What is the magnitude of the average velocity of the car (a) between point A and point B? (in m s⁻¹ to 2 s.f)

NOTE: The motion of the car is NOT an example of constant acceleration.

A car is preceding down a 1 in 10 incline at 65KPH when it's brake are abruptly applied. How far does it skid along the road before stopping if the wheels lock and the coefficient of friction between the tyres and the road is 0.7 ?

A water pump lifts water from a level 10 m below the ground.

Water is pumped at a rate of 30kg/minute with negligible velocity and friction. Calculate the minimum horsepower the engine should have for this

A straight bar 500mm long is 25 mm in diameter for the first 200mm length and 15mm diameter for the remaining length if the bar is subjected to an axial pull of 15 Kant what is the deformation of the bar

A box of mass 20 kg is kept on a smooth horizontal surface. Another object of mass 16 kilogram is kept on the box. The two objects are connected by a light inextensible string and the string goes over a smooth pulley. If a force of 6 Newtons is applied on the box, find the acceleration of the box.

Suppose we experiment with an Atwood Machine consisting of two masses m

and 2m connected by an inextensible non-slip string running over a pulley of

radius a and mass 4m, as shown below.

) Briefly discuss why no work is done by the forces of constraint. (5)

(d) What is the total energy of the system? (2)

(e) Find the acceleration dv/dt of the blocks.

Suppose we experiment with an Atwood Machine consisting of two masses m

and 2m connected by an inextensible non-slip string running over a pulley of

radius a and mass 4m, as shown below.

(a) Determine the total kinetic energy of the system. (6)

(b) Find the gravitational potential energy of the system.

A harmonic oscillator has a mass of 0.20kg and unknown spring constant,if the period is T=20g find k