A.a uniform mixture that can’t be separated
"substance" seems vague here
Answer: 0.169 (3 s.f.)
Explanation:
Force = 76 N
Spring constant = 450 N/m
Extension/displacement = x
Hooke's law states that: F = kx
Therefore, 76 = 450 X x
76/450 = x
0.169 (3 s.f.) = x
Explanation:
B. leads to muscle strain.
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