Indeed because some leave headlights off and ignore that fact since there are street lights around.
First I’ll show you this standard derivation using conservation of energy:
Pi=Kf,
mgh = 1/2 m v^2,
V = sqrt(2gh)
P is initial potential energy, K is final kinetic, m is mass of object, h is height from stopping point, v is final velocity.
In this case the height difference for the hill is 2-0.5=1.5 m. Thus the ball is moving at sqrt(2(10)(1.5))=
5.477 m/s.
Answer:
This represents radiation in ultra-violet region .
Explanation:
Energy of the orbit where n = 3 is given as follows

= -1.511 eV
Energy of the orbit where n = 1 is given as follows

= 13.6 eV
Difference of [tex]E_3 and [tex]E_1 = - 1.511+ 13.6
= 12.089 eV.
The wavelength of light having this energy in nm is given by the expression as follows
Wavelength in nm = 1244 / energy in eV
= 1244 / 12.089
= 102.90 nm
This represents radiation in ultra-violet region .
The correct answer is: Option (3) 9.8 N/kg
Explanation:
According to Newton's Law of Gravitation:
--- (1)
Where G = Gravitational constant = 6.67408 × 10⁻¹¹ m³ kg⁻¹ s⁻²
m = Mass of the body = 2 kg
M = Mass of the Earth = 5.972 × 10²⁴ kg
R = Distance of the object from the center of the Earth = Radius of the Earth + Object's distance from the surface of the Earth = (6371 * 10³) + 3.0 = 6371003 m
Plug in the values in (1):
(1)=> 
Now that we have force strength at the location, we can use:
Force = mass * gravitational-field-strength
Plug in the values:
19.63 = 2.0 * gravitational-field-strength
gravitational-field-strength = 19.63/2 = 9.82 N/kg
Hence the correct answer is Option (3) 9.8 N/kg