Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 
(b)
Answer:
(a). Index of refraction are 
= 1.344 & 
= 1.406
(b). The velocity of red light in the glass 
2.23 ×
The velocity of violet light in the glass 
2.13 ×
Explanation:
We know that
Law of reflection is
Here
= angle of incidence
= angle of refraction
(a). For red light
1 × 
= × 
= 1.344
For violet light
1 × = × 
= 1.406
(b). Index of refraction is given by
= 1.344
2.23 ×
This is the velocity of red light in the glass.
The velocity of violet light in the glass is given by
2.13 ×
This is the velocity of violet light in the glass.
Answer:
94.1 m
Explanation:
From Coulombs law,
F = Gm1m2/r²................... Equation 1
where F = force, m1 = first mass, m2 = second mass, G = universal constant, r = distance of separation.
Make r the subject of the equation,
r = √(Gm1m2/F)................. Equation 2
Given: F = 7×10² N, m1 = 15×10⁷ kg, m2 = 62×10⁷ kg,
Constant: G = 6.67×10⁻¹¹ Nm²/kg²
Substitute into equation 2
r = √( 6.67×10⁻¹¹×15×10⁷×62×10⁷/7×10²)
r √(886.16×10)
r √(88.616×10²)
r = 9.41×10
r = 94.1 m.
Hence the distance of separation = 94.1 m
5.
explanation: the answer is 5
-- It takes 100 calories of heat to make 10 grams of the stuff 20° warmer.
How much of the heat warms each gram ?
-- It takes 10 calories of heat to make each gram of the stuff 20° warmer.
How much of the heat warms that gram each degree ?
-- It takes 1/2 calorie of heat to make each gram of the stuff 1° warmer.
The specific heat of that stuff is
(1/2 calorie) per gram per °C.
That's choice-3 .
