What is the velocity of a rubber ball dropped from a rooftop after 3 seconds?

A. 0.31 m/s
B. 3.27 m/s
C. 6.8 m/s
D. 29.4 m/s

Assume that the acceleration downwards = gravitational field strength = 9.8 (2 s.f)

Assume that the mass of the ball is negligible and there is no air resistance.

Use the equation  =+1/22

s

=

u

t

+

1

/

2

a

t

2

s=height of building

t= time taken for the ball to drop

u=initial velocity ; this = 0, because when the ball is dropped it has no speed initially, however if the question had said projected instead of dropped then it must have an initial speed. In this scenario we assume it has 0 initial speed since the question says dropped.

Substitute values to equation :

s=(0*3)+(1/2*9.8*3^2)

s=(1/2*9.8*3^2)

s=44.1m

Explanation:

explanation: magnetic pole, region at each end of a magnet where the external magnetic field is strongest. the south-seeking pole, or any pole similar to it, is called a south magnetic pole. unlike poles of different magnets attract each other; like poles repel each other.

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2