Recent content by thebestrc

i probably messed up somewhere. Thanks for the help much appreciated.

oh ok. that means that the new acceleration a_2=-0.59185606 found by using the equation v^2=u^2 + 2as (u=6.25m/s s=33 v=0) when inserted into f=ma gives me f_2=-0.710227272 then inserting that into F=\mu R gives me \mu=-0.060331912. Is the working out for the other parts of the question right...

[SOLVED] Mechanics question-Momentum&F=ur Homework Statement An ice hockey player is required to strike a puck having a mass of 1.2 kg, so that it is accelerated uniformly from rest across a smooth ice rink surface so as to cover a distance of 25 m in 8 s. The puck travels another 8...

yes .thank you again. I don't know what's wrong with me today it's always the simple ones that put me off.

Stupid me. I worked it out wrong. the answer should be 0.785m(3sf). vsin\theta t - 1/2at^2 theta = 0 because its horizontal. a=-9.81 t=0.4s insert into equation and the answer should be 0.7848m.

[SOLVED] Arrow- Finding the point of impact Homework Statement An archer shoots an arrow horizontally parallel to the ground at a height of 1.5 m, above the ground, aimed directly at the centre of a target marked on a vertical wood panel situated 30 m from the archer. The arrow is released...

Thanks for the help. I've been at uni for a year now and this stuff still puzzles me.

oh ok. me thinks i interpretated the question. Thanks. that means t=0.008s. I thought a= -9.81m/s since the effects of air/wind resistance are ignored? I think this is the right answer for retarding force: -393.75N I got it by working out a instead of using -9.81 , and i got -8750 which...

I've worked out the total distance traveled by the arrow which is 250m . I found this out using the equation v^2=u^2 +2as . I then substitute it into the equation you gave me and i still get 7.14 (3sf). u=70 , a=-9.81 s= 250 (including distance penetrated)

[SOLVED] Average Retarding Force Problem Homework Statement An arrow of mass 45 g strikes a wood block target horizontally with a velocity of 70 ms-1 and penetrates a distance of 280 mm. Ignoring air resistance, calculate (a) the time it takes for the arrow to stop moving, and (b) the...