If the 30 N on the rope were pulled straight up, it would offset the force of gravity ( m g = 10 kg * 9.8 N/kg = 98 N) , leaving a net force up from the ground on the sled of 98-30 = 68 N. Since the rope is pulled at the angle of 25o, only part of the force is in the upward direction, (30N)(sin(25) = (30)(.423) = 12.7. So the net force becomes 98 N down offset by 12.7 up or 98-12.7 = 85.3 N. Ah, there it is: C.
Answer:
First Question
Second Question
The wavelength is for an X-ray
Explanation:
From the question we are told that
The width of the wall is 
The first excited state is 
The ground state is 
Gnerally the energy (in MeV) of the photon emitted when the proton undergoes a transition is mathematically represented as
![E = \frac{h^2 }{ 8 * m * l^2 [ n_1^2 - n_0 ^2 ] }](https://tex.z-dn.net/?f=E%20%20%20%3D%20%20%20%5Cfrac%7Bh%5E2%20%7D%7B%208%20%2A%20m%20%20%2A%20%20l%5E2%20%5B%20n_1%5E2%20-%20n_0%20%5E2%20%5D%20%7D)
Here h is the Planck's constant with value 
m is the mass of proton with value 
So
![E = \frac{( 6.626*10^{-34})^2 }{ 8 * (1.67 *10^{-27}) * (10 *10^{-15})^2 [ 2^2 - 1 ^2 ] }](https://tex.z-dn.net/?f=E%20%20%3D%20%20%20%5Cfrac%7B%28%206.626%2A10%5E%7B-34%7D%29%5E2%20%7D%7B%208%20%2A%20%281.67%20%2A10%5E%7B-27%7D%29%20%20%2A%20%20%2810%20%2A10%5E%7B-15%7D%29%5E2%20%5B%202%5E2%20-%201%20%5E2%20%5D%20%7D)
=>
Generally the energy of the photon emitted is also mathematically represented as
=> 
=> 
=> 
Generally the range of wavelength of X-ray is 
So this wavelength is for an X-ray.
Answer:
350N
Explanation:
Given parameters:
Mass of the man = 125kg
Mass of the watermelon = 6kg
Mass of cantaloupe = 3kg
Mass of potatoes = 6kg
Acceleration = 2.5m/s²
Unknown:
Force required to get home = ?
Solution:
To find this force we use;
Force = mass x acceleration
mass = 125 + 6 + 3 + 6 = 140kg
So;
Net force = 140 x 2.5 = 350N
Answer:
<h3> b. 1.18</h3>
Explanation:
The fundamental frequency in string is expressed as;
F1 = 1/2L√T/m .... 1
L is the length of the string
T is the tension
m is the mass per unit length
If the tension is increased by 40%, the new tension will be;
T2 = T + 40%T
T2 = T + 0.4T
T2 = 1.4T
The new fundamental frequency will be;
F2 = 1/2L√1.4T/m ..... 2
Divide 1 by 2;
F2/F = (1/2L√1.4T/m)/1/2L√T/m)+
F2/F = √1.4T/m ÷ √T/m
F2/F = √1.4T/√m ×√m/√T
F2/F = √1.4T/√T
F2/F = 1.18√T/√T
F2/F = 1.18
F2 = 1.18F
Hence the fundamental frequency of vibration changes by a factor of 1.18
