Part A)
As we know that spring force is given by
F = kx
here x = stretch in the spring from natural length
So here when spring reaches to its natural length
Force due to spring = 0
so acceleration = 0
Part b)
When spring is compressed from its natural length it will have elastic potential energy in it
so it is given by
now we know that there is no friction in it so maximum kinetic energy of the launcher must be equal to the elastic potential energy of the spring
here we have
k = 70 N/m
x = 0.4 m
Part c)
Now to find the speed we know that
so its speed is 6.11 m/s
<span>1. 10x
2. fault line
3. UV Waves
4. through solids and liquids
5. inner core
6. low temperature
7. cinder cone
8. earth's core
9. they are all caused by plate movement
10. inner mantle
11. transverse
12.divergent
13. none of these
14. fault
15. Lithospheric plates
16. foreshocks and aftershocks can happen at the same time
17. stratosphere
18. this question is not complete</span>
Answer:
Number of electrons, 
Explanation:
It is given that,
Resistance, R = 4 ohms
Current, I = 3 A
Time, t = 5 min = 300 s
We need to find the number of electrons pass through the resistor during this time interval. Let the number of electron is n.
i.e. q = n e ...............(1)
And current, 
e is the charge of an electron
So, the number of electrons pass through the resistor is 
. Hence, this is the required solution.
Ok so we know:
The time (t) is 18seconds
The acceleration (a) is 2.2m/s2
The displacement (r) is 660
Using the equation
With 'u' being the initial velocity we want, we get:
So:
So:
So the original/initial velocity was 16.8666 or 16.87 m/s
Hope this helped
Answer:
Incorrect statement is (b).
Explanation:
Option (a) : There is an inverse relation between the time and the frequency. The time taken depends on the frequency of the number of oscillations. Statement 1 is correct i.e. the time taken by any point of the wave to make one complete oscillation does not depend on the amplitude.
Option (b) : Speed of a wave is given by the product of its frequency and wavelength. It is not necessary that doubling the wavelength of the wave will halve its frequency as speed depends on the medium.
Option (c) : Doubling the amplitude has no effect on on the wavelength as amplitude does not depends on its wavelength.
Option (d) : Since, 
Speed is directly proportional to the frequency and wavelength. So, doubling the frequency of the wave will double its speed. So, the incorrect statement is (b).
