Mechanics | Relativity Answers

A spherical buoy of diameter 0.5 m and mass 35 kg is attached to the seabed by a mooring rope and floats fully submerged as shown to the right. Calculate the tension in the mooring rope. The density of sea water is 1020 kgm−3.

A uniform string of length 20 m is suspended from a rigid support. A short wave pulse is introduced at its lowest end. It starts moving up the string. The time taken to reach the support is
(take g = 10 m/s2)

13 A uniform plank AB 30 m long, weighing 100 N is pivoted at points P, Q which are 5 m from the ends A and B respectively. A boy of weight 250 N stands at a point D on the plank, 1 m away from Q and the arrangement is in equilibrium. Determine the reaction
R 1
R1
and
R 2
R2
at the supports.


77.5 N, 245.5 N
105.5 N 33.5 N
37.5 N, 312.5 N
27.5 N, 232.5 N

2) You drive 7.50 km in a straight line in a direction 15º east of
north. (a) Find the distances you would have to drive straight east and then straight north to arrive at the same point. (This determination is equivalent to find the components of the displacement along the east and north directions.) (b) Show that you still arrive at the same point if the east and north legs are reversed in order.

A candle of diameter d is floating on a liquid in a cylindrical container of diameter D (D>>d). If it is burning at the rate of 2cm/hr then what will be the resultant ht of the candle?

An internal combustion engine uses fuel, of energy content 44.4 MJ/kg, at a rate of 5 kg/h. If the efficiency is 28%, determine the power output and the rate of heat rejection.

A football quarterback runs 15.0 m straight down the playing field in 2.50 s. He is then hit and pushed 3.00 m straight backward in 1.75 s. He breaks the tackle and runs straight forward another 21.0 m in 5.20 s. Calculate his average velocity (a) for each of the three intervals and (b) for the entire motion c) What is his total displacement? What is his total distance?

At the end of a race, a runner decelerates from a velocity of 9.00 m/s at a rate of 2.00 m/s2 . (a) How far does she travel in the next 5.00 s? (b) What is her final velocity? (c) Evaluate the result. Does it make sense?

A powerful motorcycle can accelerate from rest to 26.8 m/s (100 km/h) in only 3.90 s. (a) What is its average acceleration? (b) How far does it travel in that time?

a truck is moving east ward with a velocity of 15 m/s find the mass of the truck.if the momentum of the truck is 30000kg m/s.find the mass of the truck