Aspider crawling across a table leaps onto a magazine blocking its path. the initial velocity of the spider is 0.870 m/s at an angle of 35.0â° above the table, and it lands on the magazine 0.0770s after leaving the table. ignore air resistance. how thick is the magazine? express your answer in millimeters.

Thickness of magazine = 9.42 mm.

Explanation:

Considering vertical motion of spider:-

Initial velocity, u =  0.870 sin 35 = 0.5 m/s

Acceleration , a = -9.81 m/s²

Time, t = 0.077 s

We have equation of motion s= ut + 0.5 at²

Substituting

   s= 0.5 x 0.077 - 0.5 x 9.81 x 0.077²

    s = 9.42 x 10⁻³ m = 9.42 mm

Thickness of magazine = 9.42 mm.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

no. dot product   =0 when vecs at right angles