Answer:
The cord will break at the lower point.
The linear velocity:
Explanation:
The cord will break at the lower point, as this point is where the maximum tension will be at any given speed. This is because at the lower point to maintain the circular movement the cord must withstand the centripetal force plus the gravity force that goes on the opposite direction. To explain this, to maintain the circular movement the stone must always be subjected to a resultant force equal to the centripetal force:
(1)
This is constant for a given speed and radius. The total force is the sum of all the forces on the stone, in this case the gravitational force(W) and the cord tension(T). On the upper point they are on the same direction:
On the lower point they have opposite directions:
(2)
As the centripetal force and weight are constant for a given speed and radius, the tension on the lower point is bigger.
As the cord will break at 33N at the lower point, from (2):
replacing on (1):
The linear velocity:
Answer: The balls would hit the ground at the same time.
Explanation: Since there is no air resistance, we would put Galileo's experiment into motion. Galileo once performed an experiment of dropping two items, with different masses, from the tower of Pisa. Since there was no air resistance, the balls hit the ground at the same time. In this problem, the balls are "free-falling." Freefall is a term used in Physics to describe the motion of a falling object experiencing only the acceleration due to gravity. g=9.8 m/s^2 (acceleration due to gravity.) 9.8 will always be the acceleration in a free fall event like this with no air resistance, since Gravity remains constant.
Newton's second law of motion states that F=ma, (force is equal to mass times acceleration), but since Newton also states that f=mg, we can conclude that ma=mg. Stating that no matter what the mass of the object is, both of the objects will fall at the same time with the same velocity.
Endothermic is when heat is absorbed, so like when ice turns into water, it absorbed heat and energy from the air because now the molecules in the ice started moving faster and more freely to become a liquid state.
Answer:
the crown was not made of pure gold
Explanation:
Mass of gold = weight in air/ g = 7.84N/10ms-2= 0.784 Kg or 0.8Kg
From Archimedes principle:
Upthrust= weight in air- weight in a fluid
Upthrust= volume × density × g
Note density of water = 1000kgm-3
7.84-6.84= V × 1000kgm-3×10ms-2
V= 1/10000= 1×10-4 m^3
Density = mass/ volume= 0.8/1×10-4
= 8×10^3 Kgm-3
But we know the density of gold to be 19.3 ×10^3 kgm-3
Hence the crown was not made of pure gold
The formula of the kinetic energy is KE = 0.5*m*v^2.
Given m = 80 kg and KE = 4000 J,
4000 = 0.5*80*v^2
v^2 = 100
v = 10 m/s
