Answer:
88.34 N directed towards the center of the circle
Explanation:
Applying,
F = mv²/r................... Equation 1
F = Force needed to keep the mass in a circle, m = mass of the mass, v = velocity of the mass, r = radius of the circle.
But,
v = 2πr/t................... Equation 2
Where t = time, π = pie
Substitute equation 2 into equation 1
F = m(2πr/t)²/r
F = 4π²r²m/t²r
F = 4π²rm/t²............. Equation 3
From the question,
Given: m = 0.8 kg, r = 0.7 m, t = 0.5 s
Constant: π = 3.14
Substitute these values into equation 3
F = 4(3.14²)(0.7)(0.8)/0.5²
F = 88.34 N directed towards the center of the circle
Answer:
D.
For every action there is an equal and opposite reaction.
Explanation:
im doing the same one lol
The crate moves at constant velocity, this means that its acceleration is zero, so the net force acting on the crate is zero (Newton's second law).
There are only two forces acting on the crate: the force F applied by the worker and the frictional force, acting in the opposite direction:
, where
is the coefficient of friction and
is the mass of the crate. Since the net force should be equal to zero, the two forces must have same magnitude, so we have:
And so, this is the force that the worker must apply to the crate.
Answer:
Emissions from power plants that burn fossil fuels increase atmospheric carbon dioxide, which is absorbed by the ocean.
Explanation:
Fossil fuels are burnt in power plants in order to produce energy. These fossil fuels contain carbon. Combustion of these fossil fuels emits oxides of carbon into the atmosphere. The oxides of carbon are carbon II oxide and carbon dioxide.
Carbon dioxide can be absorbed by the ocean to form carbonic acid according to the reaction equation;
CO2(aq) + H2O(l) ------> H2CO3(aq)
This is an anthropogenic activity which increases ocean acidification.
Answer:
Explanation:
dU= dq+w
dU is change in internal energy of the system
dq is the amount heat added or released by the system which be positive or negative respectivelý
And w is the amount of work done by the system or on the system which will be positive or negative respectively.
Hence,
dU= 250+80= 330 J
The change will be positive
