Question

A brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 N on him. The mass of the losing player plus equipment is 90.kg and he is accelerating at 1.20m/s^2 backward. A) what is the force of friction between the losing player's feet and the grass? b) What force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? c) Draw a sketch of the situation showing the system of interest used to solve each part. For this situation, draw a free-body diagram and write the net force eqation.

Answer 1

Answer : -

Given that

Among the many bissionproducts that may be extracted chemically from the spent fuel a nuclear reaction is

90_sr ( T 1 / 2 = 29 y )

The equation of the decay is sk 90 is

90_sr38 -> 90y39 + ^oe_-1 + Ve

Here e^o_-1 = negative B - particle or electrons

Ve = antineuttino

and mass of Sr - 90 = 89.90773 amu

mass of Y - 90 = 89.907151 amu

m,ass of e^o_-1 = 0.0005485 amu

Now, mass defect = mass of reactans - mass of products

= [ 89.907737 - ( 89.907151 + 0.000598) ]

= therefore Qeff = [ -0.000088 x 931 ] mev

= - 0.0350 Mev

The reaction is exothermic because Q - value is -Ve.