Moustapha jones reaches the bottom of a hill on his bike moving at a speed of 8.6 m/s when his chain breaks. he coasts up the hill until he comes to a stop after 3.5 s. find his acceleration while on the hill, and the distance he travelled up the hill.

1. Answer;

Acceleration is;

-2.46m/s²

Explanation;

The initial velocity is 8.6 m/s, the final velocity = 0 m/s

The time is 3.5 seconds

Using the equation;

V =U + at

but V =0 , -U = at

a = -U/t = -8.6 /3.5

= -2.457 m/s²

= -2.46 m/s² (2 d.p)

2. Answer;

The distance is ;

=15.1 m

Solution;

a = -2.46 m/s², v=0 and U = 8.6 m/s

Using the equation;

V² = U² +2as (where s is the distance)

but v =0, thus, s =U²/2a

= -8.6²/ 2(-2.46)

= -73.96 /-4.92

= 15 .1 m (1 d.p)

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it