A motorboat accelerates uniformly from a velocity of 6.5m/s
to the west to a velocity of 1.5m/s to the west. if its accelerate was 2.7m/s2
to the east ,
how far did it travel during the accelration? Give your
answer in units of kilometers per hour/sec. To find the acceleration of the car
we have to
<span>
1. First determine
the suitable formula for this word problem.
Which is a. A=vf-vi/t</span>
which will be
Given are: Vi= 6.5 m/s Vf= 1.5 m/s a= 2.7 m/sec2 t=1.85s
Solution:
<span>
x = v0t + ½at2</span>
<span>x = <span>16.645375 m </span></span>
Answer:
m = 0.4 [kg]
Explanation:
Weight is considered as a force and this is equal to the product of mass by gravitational acceleration.

where:
W = weight = 0.8 [N]
m = mass [kg]
g = gravity acceleration 2[N/kg]
Therefore:
![m=W/g\\m = .8/2\\m = 0.4 [kg]](https://tex.z-dn.net/?f=m%3DW%2Fg%5C%5Cm%20%3D%20.8%2F2%5C%5Cm%20%3D%200.4%20%5Bkg%5D)
Answer:
a) The student must run flight of stairs to lose 1.00 kg of fat 709.5 times.
b) Average power
P(w)= 1062.07 [w]
P(hp)=1.42 [hp]
c) This activity is highly unpractical, because the high amount of repetitions he has to due in order to lose, just 1 Kg of fat.
Explanation:
First, lets consider the required amount of work to move the mass of the student. (considering running stairs just as a vertical movement)
Work:

Where m is the mass of the student, g is gravity (9.8 m/s) and d is the total distance going up the stairs (0.15m *85steps= 12.75m )
![W= F*d= m*g*d=85* 9.8*12.75=10620.75 [J]](https://tex.z-dn.net/?f=W%3D%20F%2Ad%3D%20m%2Ag%2Ad%3D85%2A%209.8%2A12.75%3D10620.75%20%5BJ%5D)
Converting from Joules to Kcals:

Now lets take into account the efficiency of the human body (20%)
2.537 ---> 20%
x ---> 100%

So the student is consuming 12.685 KCals each time he runs up the stairs.
Now,
1 g --> 9 Kcals
1000 g --> 9000KCals
Burning 1 g of fat, requieres 9 KCals, 1000g burns 9000KCals. So in order to burn a 1Kg of fat:

He must run up the stairs 709.5 times, to burn 1 Kg of fat.
********************
For b) just converting units, taking into account the time lapse. (53103.75 is the 100% of the energy in joules, from converting 12.685Kcals to joules)
![Power=\frac{Joules}{Seconds} =\frac{53103.75}{50} =1062.075 [W]\\](https://tex.z-dn.net/?f=Power%3D%5Cfrac%7BJoules%7D%7BSeconds%7D%20%3D%5Cfrac%7B53103.75%7D%7B50%7D%20%3D1062.075%20%5BW%5D%5C%5C)
![P(hp)=\frac{P(w)}{745.7} =\frac{1062.075}{745.7} =1.42[hp]](https://tex.z-dn.net/?f=P%28hp%29%3D%5Cfrac%7BP%28w%29%7D%7B745.7%7D%20%3D%5Cfrac%7B1062.075%7D%7B745.7%7D%20%3D1.42%5Bhp%5D)
*****
Answer:
Option a
Explanation:
The three basic and major points of the kinetic theory of gases are listed below:
1. In the collision between the gas molecules, no loss or gain of energy takes place.
2. According to the theory, the gaseous molecules exhibits constant and linear motion.
3. The molecules of the gas occupies very little space as compared to the container. Thus the empty space in a gas is not very little.
Having the ability to deal with people in a way that does not offend them