Explanation:
The given data is as follows.


Electric potential energy (
) = ?
Formula to calculate electric potential energy is as follows.
= 
= 
Thus, we can conclude that the electric potential energy of the pair of charges when the second charge is at point b is
.
Answer:
about 4 km
Explanation:
15 minutes is a quarter of an hour, so you divide 16km by 4 to get your answer
Answer:
1497×10⁵ km
Explanation:
Speed of light in vacuum = 3×10⁵ km/s
Time taken by the light of the Sun to reach the Earth = 8 min and 19 s
Converting to seconds we get
8×60+19 = 499 seconds
Distance = Speed × Time

1 AU = 1497×10⁵ km
The Sun is 1497×10⁵ km from Earth
Answer:
A) d = 11.8m
B) d = 4.293 m
Explanation:
A) We are told that the angle of incidence;θ_i = 70°.
Now, if refraction doesn't occur, the angle of the light continues to be 70° in the water relative to the normal. Thus;
tan 70° = d/4.3m
Where d is the distance from point B at which the laser beam would strike the lakebottom.
So,d = 4.3*tan70
d = 11.8m
B) Since the light is moving from air (n1=1.00) to water (n2=1.33), we can use Snell's law to find the angle of refraction(θ_r)
So,
n1*sinθ_i = n2*sinθ_r
Thus; sinθ_r = (n1*sinθ_i)/n2
sinθ_r = (1 * sin70)/1.33
sinθ_r = 0.7065
θ_r = sin^(-1)0.7065
θ_r = 44.95°
Thus; xonsidering refraction, distance from point B at which the laser beam strikes the lake-bottom is calculated from;
d = 4.3 tan44.95
d = 4.293 m
<em>Answer</em>
Force = 170 N
<em>Explanation</em>
First find the distance (d) travelled by the bulldozer.
Sin 35 = 15/d
d = 15/(sin 35)
= 26.15m
Now;
work done = force × distance.
4500 J = force × 26.15
dividing both sides by 26.15,
Force = 4500/26.15
= 172.07 N
Answer to two significant figures = 170 N