Answer:
a. The student's mistake was that the student did not swing the pendulum and start the watch at the same time.
b. 1.2 s per swing.
c. The likely effect of her reaction time is that they will should subtract two seconds off the time.
Explanation:
This was kinda hard thinking it might be that the new force is going to 4 times bigger than the original one.
The focal length of the lens is 25cm
given:
power,p=4 diopters
what is focal length?
Focal length is the distance between the point of convergence of your lens and the sensor or film recording the image.
what is diopter?
The unit of optical power of lens is called diopter.It is the optical power of the lens.
we know,
p=1/f
where,
p= power
f= focal length
f=1/p
f=1/4
=0.25m
=25cm
Thus,the focal length of the lens is 25cm
learn more about focal length from here: https/brainly.com/question/28203589
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Answer:
t = 300.3 seconds
Explanation:
Given that,
The mass of a freight train, ![m=1.01\times 10^7\ kg](https://tex.z-dn.net/?f=m%3D1.01%5Ctimes%2010%5E7%5C%20kg)
Force applied on the tracks, ![F=7.5\times 10^5\ N](https://tex.z-dn.net/?f=F%3D7.5%5Ctimes%2010%5E5%5C%20N)
Initial speed, u = 0
Final speed, v = 80 km/h = 22.3 m/s
We need to find the time taken by it to increase the speed of the train from rest.
The force acting on it is given by :
F = ma
or
![F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{1.01\times 10^7\times (22.3-0)}{7.5\times 10^5}\\\\t=300.3\ s](https://tex.z-dn.net/?f=F%3D%5Cdfrac%7Bm%28v-u%29%7D%7Bt%7D%5C%5C%5C%5Ct%3D%5Cdfrac%7Bm%28v-u%29%7D%7BF%7D%5C%5C%5C%5Ct%3D%5Cdfrac%7B1.01%5Ctimes%2010%5E7%5Ctimes%20%2822.3-0%29%7D%7B7.5%5Ctimes%2010%5E5%7D%5C%5C%5C%5Ct%3D300.3%5C%20s)
So, the required time is 300.3 seconds.
Explanation :
Displacement refers to the distance between the final and the initial position. Hence the displacement of the ball will be the difference between the initial and the final displacement.
Let the initial position be 0.
Final position = 8 cm
So the difference between initial position and final position = 0 – 8 = - 8 cm.
So the billiard ball comes to rest 8.0 cm behind its orbital position.