<span>The discoveries Mme Curie made were of great benefit to physics, chemistry and medicine. During the time she was doing her research, the health effects of ionizing radiation were not known. The amount of radiation that she was exposed to led to her death. Even today her notebooks and other personal effects are highly contaminated with radioactive material.
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Work, scientifically speaking, is done when a force is applied to an object which consequently moves the object at a certain direction. Work in formula, is force multiplied with distance.
W = F x d
The Potential energy stored in the system is 1 J
<u>Explanation:</u>
Given-
Mass, m = 4 kg
Spring constant, k = 800 N/m
Distance, x = 5cm = 0.05m
Potential energy, U = ?
We know,
Change in potential energy is equal to the work done.
So,

By plugging in the values we get,

Therefore, Potential energy stored in the system is 1 J
Answer:
1 N
Explanation:
Buoyant Force: This is also called upthrust, It can be defined as the force which act upward exerted by a fluid when an object is placed in it.
The S.I unit is Newton.
From the question,
Buoyant force = Weight of the object in air- weight of the object when submerged in water.
U = W-W'.......................... Equation 1
Where U = upthrust, W = weight in air, W' = weight when submerged in water.
Given: W = 3 N, W' = 2 N
Substitute into equation 1
U = 3-2
W = 1 N
Answer:
1) F = 24 N
2) Distance = 1 m
Explanation:
We are given;
Mass; m = 120 g = 0.12 kg
Initial velocity; u = 20 m/s
Final velocity; v = 0 m/s since it came to rest.
Time; t = 0.1 s
We can calculate acceleration from Newton's first equation of motion;
a = (v - u)/t
a = (0 - 20)/0.1
a = -200 m/s²
1) magnitude of the resistance will be;
F = ma
F = 0.12 × (-200)
F = -24 N
Since, we are dealing with the magnitude, we will take the absolute value. Thus, F = 24 N
2) To find the distance moved by the bullet, we know that;
Distance = Average speed × time
Thus;
Distance = ((v + u)/2) × t
Distance = ((0 + 20)/2) × 0.1
Distance = 1 m