• Difficult Problems in physics From post utme (Unilorin 2007)

    Physics

    Chima Sunday (Tutor)
    04-04-2016 17:20:00 +0000

    About 85% that attempted these questions got it wrong, try and see if you can be able to get it right. Question 1 A car accelerates from 3m/s to 100m/s in 35s. Calculate the acceleration of the car.
    Option A 2.0ms^2
    Option B 3ms^2
    Option C 4ms^2
    Option D 5ms^2
    solution
    recall that acc = final velocity(v) - initial velocity(u) divided by change in time
    i.e acc = (v - u)/t = (100 - 3)/35 = 2.8 = 3m/s^2
    so correct option is B

    Question 2 A body of mass 2kg moves round a circle of radius 2m with a constant speed of 10m/s. Calculate the force toward the centre..
    Option A 40N
    Option B 50N
    Option C 80N
    Option D 100N
    solution
    the force that acts toward the center is centripetal force
    so F(c) = mv2/r
    m = 2kg, r = 2m and v = 10m/s
    so F = 2*10^2/2 = 10^2 = 100N
    so correct option is D



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