Answer:
Magnitude of static friction force is 70 sin40° = 44.99 N.
No, it is not necessary that it is maximum static friction.
Normal force is equal to 70 cos40° = 53.62 N.
Explanation:
We apply newton law of moton equation along the plane and perpendicular to plane;
Along the plane,
70 sin 40° = 
---------------(1)
70 cos 40° = N --------------(2)
= μN -----------------(3)
So, it depends on the value of μ that the friction is maximum or not .
Answer: 430 nm.
Explanation:
The relation of wavelength and frequency is:
Formula used : 
where,
= frequency =
= wavelength = ?
c = speed of light = 
Now put all the given values in this formula, we get
Thus the wavelength (in nm) of the blue light emitted by a mercury lamp is 430 nm.
12 protons in the nucleus
Work = force in the direction of the movement x distance = 27 N x 1.7 m
Work = 45.9 joules
Answer: option c.
