Answer:
2.8 m/s
Explanation:
Energy of a system cannot be destroyed . It can only be transfer to another form of energy.
when the pendulum is at rest in a height 0.4 m , it has a potential energy due to the height it is. but no kinetic energy since ni movement (velocity)
at the time it reach the lowest point of the path , we can say that it is in the minimum potential level , therefore it now does not have any potential energy , but has a kinetic energy
energy at rest = energy at lowest point
KE1 + PE1 = KE2 + PE2
0 + 1.5 * 9.8 *0.4=
V=√(2*9.8*0.4)
V = 2.8 m/s
Heating up the brake pads of a car due to friction, is an example of conversion of work done against friction into thermal energy.
A moving car has kinetic energy. When the brakes are pressed, they exert friction against the rim of the wheel. The brake pads exert a force of friction on the wheels. The force of friction decelerates the car. As the car continues forward for a certain time based on its initial velocity, work is done against the frictional force. The kinetic energy possessed by the car is spent in doing the work against friction. This work done is converted into heat, which heats up the braking pads.
Thus, heating up the brake pads of a car is an example of conversion of its initial kinetic energy into thermal energy, by doing work against friction.
Given that,
Mass of a water balloon, m = 1 kg
It comes downward an experience a 4.9 N air resistance as it approaches the ground.
To find,
The acceleration of the water balloon when it experiences this air resistance.
Solution,
Let the acceleration be a.
The net force acting on it will be :
The force is also given by :
F = ma
So, the acceleration of the water balloon is .
Chemical equation
Explanation:
A chemical equation is an expression that represents a chemical reaction. The formula of the reactants are connected by an arrow with the formula for the products.
Chemical reactions are made up of reactants and products which all together forms a chemical equation.
- The reactants are positioned on the left hand side of a chemical equation. It is the specie that forms the product.
- The products are on the right hand side and they are the result of a chemical change.
Learn more:
Chemical equation brainly.com/question/8926688
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First of all, to work out the velocity at the bottom you can use the conservation of energy principle as friction isn't specified. So U = T or mgh =
, rearranging to get
. From this you get v = 11.72
. Following angular velocity ω =
which you can use to get ω = 6.9
.
Hope that helps