A 65.0-kg woman steps off a 10.0-m diving platform and drops straight down into the water. 1) If she reaches a depth of 3.20 m,
1 answer:
Answer:
F=2627.6N
Explanation:
The work done by this resistive force while traveling a distance <em>d</em> underwater would be:
where the minus sign appears because the force is upwards and the displacement downwards.
This work is equal to the change of mechanical energy. At the diving plataform and underwater, when she stops moving, the woman has no kinetic energy, so all can be written in terms of her total change of gravitational potential energy:
Putting all together:
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a) For the motion of car with uniform velocity we have , , where s is the displacement, u is the initial velocity, t is the time taken a is the acceleration.
In this case s = 520 m, t = 223 seconds, a =0
Substituting
The constant velocity of car a = 2.33 m/s
b) We have
s = 520 m, t = 223 seconds, u =0 m/s
Substituting
Now we have v = u+at, where v is the final velocity
Substituting
v = 0+0.0209*223 = 4.66 m/s
So final velocity of car b = 4.66 m/s
c) Acceleration = 0.0209
As we know that here no air resistance while ball is moving in air
So here we will say that
initial total energy = final total energy
here we know that
(as it will be on ground at initial and final position)
so we will say
since mass is always conserved
so we will say that final speed of the ball must be equal to the initial speed of the ball
so we have