<span>1. By Ilkka Cheema<span><span>2. </span>Newton’s 1st Law The first law of motion sates that an object will not change its speed or direction unless an unbalanced force (a force which is distant from the reference point) affects it. Another name for the first law of motion is the law of inertia. If balanced forces act on an object it doesn’t accelerate or change direction. This means it doesn’t change its velocity and it doesn’t have momentum.</span><span><span>3. </span>Examples of Newton’s 1st Law If you slide a hockey puck on ice, eventually it will stop, because of friction on the ice. It will also stop if it hits something, like a player’s stick or a goalpost. If you kicked a ball in space, it would keep going forever, because there is no gravity, friction or air resistance going against it. It will only stop going in one direction if it hits something like a meteorite or reaches the gravity field of another planet. If you are driving in your car at a very high speed and hit something, like a brick wall or a tree, the car will come to an instant stop, but you will keep moving forward. This is why cars have airbags, to protect you from smashing into the windscreen.</span><span><span>4. </span>Newton’s 2nd Law The second law of motion states that acceleration is produced when an unbalanced force acts on an object (mass). The more mass the object has the more net force has to be used to move it.</span><span><span>5. </span>Examples of Newton’s 2nd Law If you use the same force to push a truck and push a car, the car will have more acceleration than the truck, because the car has less mass. It is easier to push an empty shopping cart than a full one, because the full shopping cart has more mass than the empty one. This means that more force is required to push the full shopping cart.</span><span><span>6. </span>Newton’s 3rd Law The third law of motion sates that for every action there is a an equal and opposite reaction that acts with the same momentum and the opposite velocity.</span><span><span>7. </span>Examples of Newton’s 3rd Law When you jump off a small rowing boat into water, you will push yourself forward towards the water. The same force you used to push forward will make the boat move backwards. When air rushes out of a balloon, the opposite reaction is that the balloon flies up. When you dive off of a diving board, you push down on the springboard. The board springs back and forces you into the air.</span></span>
Answer:
a) if we assume that the water does not spill, Beaker B weighs more than beaker S, or which in this case Beaker A weighs more
b) If it is spilled in water the weight of the two beakers is the same
Explanation:
The beaker weight is
beaker A
W_total = W_ empty + W_water
Beaker B
W_total = W_ empty + W_water + W_roca
a) if we assume that the water does not spill, Beaker B weighs more than beaker S, or which in this case Beaker A weighs more
b) If it is spilled in water, the weight of the two beakers is the same because the amount of liquid spilled and equal to the weight of the stone, therefore the two beakers weigh the same
Answer: 1.14 N
Explanation :
As any body submerged in a fluid, it receives an upward force equal to the weight of the fluid removed by the body, which can be expressed as follows:
Fb = δair . Vb . g = 1.29 kg/m3 . 4/3 π (0.294)3 m3. 9.8 m/s2
Fb = 1.34 N
In the downward direction, we have 2 external forces acting upon the balloon: gravity and the tension in the line, which sum must be equal to the buoyant force, as the balloon is at rest.
We can get the gravity force as follows:
Fg = (mb +mhe) g
The mass of helium can be calculated as the product of the density of the helium times the volume of the balloon (assumed to be a perfect sphere), as follows:
MHe = δHe . 4/3 π (0.294)3 m3 = 0.019 kg
Fg = (0.012 kg + 0.019 kg) . 9.8 m/s2 = 0.2 N
Equating both sides of Newton´s 2nd Law in the vertical direction:
T + Fg = Fb
T = Fb – Fg = 1.34 N – 0.2 N = 1.14 N
Answer:
C
Explanation:
Radiation affects both cancer cells and healthy cells, but it affects cancer cells more.
Answer:
Density (φ) = 0,8827 Kg/L
Specific weight (Ws) = 8,65 N/L
Specific gravity (Gs) = 0,8827 (without unit)
Explanation:
The density formula: φ = 
I know the mass "m", I need to find out the volume of the cylinder (V)
V = π* r²*h
The radius "r" is equal to half the diameter (150mm) = 75mm
Now I can find out the density (φ)
φ = 
= 0,8827 Kg/L
The specific weight (Ws) is the relationship between the weight of substance (oil) and its volume. We apply the following formula:
Ws = φ*g
(g = gravity = 9,8 m/s²)
Finally, specific gravity (Gs) is the ratio between the density of a substance (oil) "φ(o)" and the density of water "φ(w)" :
Gs = φ(o) / φ(w)
(φ(w) = 1 Kg/L
Hope this can help you !!
