Aparachutist bails out and freely falls 62 m. then the parachute opens, and thereafter she decelerates at 2.5 m/s2. she reaches the ground with a speed of 2.8 m/s. (a) how long is the parachutist in the air

16.4 s

Explanation:

For AB

initial velocity, u = 0

final velocity, v = ?

acceleration, a = 9.8 m/s^2

distance, s = 62 m

Let the time taken is t.

Use second equation of motion

t = 3.56 s

Use first equation of motion

v = u + at

v = 0 - 9.8 x 3.56

v = - 34.89 m/s

For BC

Let the time taken is t'

initial velocity, v = 34.89 m/s

final velocity, v' = 2.8 m/s

a = 2.5 m/s^2

use first equation of motion

v' = v + a t'

2.8 = 34.89 - 2.5 t'

t' = 12.84 s

So, the total time taken

T = t + t' = 3.56 + 12.84 = 16.4 s

Dis the

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current