Answer:
(a) 1767.43 N
(b) 182.45 N
Explanation:
Radius of earth, R = 6450 km
Weight of person, W = 7070 N
mass of person, m = W / g = 7070 / 9.8 = 721.4 kg
(a) h = 6450 km
The value of acceleration due to gravity on height is given by


g' = g / 4 = 9.8 / 4 = 2.45 m/s^2
The weight of the person at such height is
W' = m x g' = 721.4 x 2.45
W' = 1767.43 N
(b) h = 33700 km
The value of acceleration due to gravity on height is given by


g' = g x 0.0258 = 9.8 x 0.0258 = 0.253 m/s^2
The weight of the person at such height is
W' = m x g'
W' = 721.4 x 0.253
W' = 182.45 N
To increase the number of snowmen destroyed, you would want more energy and all of the above would increase the energy of the system so D.
Since you already gave us the weight of the 2.5-kg box,
we don't even need to know what the distance is, just
as long as it doesn't change.
Look at the formula for the gravitational force:
F = G m₁ m₂ / R² .
If 'G', 'm₁' (mass of the Earth), and 'R' (distance from the Earth's center)
don't change, then the Force is proportional to m₂ ... mass of the box,
and you can write a simple proportion:
(6.1 N) / (2.5 kg) = (F) / (1 kg)
Cross-multiply: (6.1 N) (1 kg) = (F) (2.5 kg)
Divide each side by (2.5 kg): F = (6.1N) x (1 kg) / (2.5 kg) = 2.44 N .
Answer
By F = -kx {-ve just indicating the sign of the force}
=>35 = k x (85-50) x 10^-2
=>k = 100 N/m
Again by F = -kx