Answer:
V at C is 3.6 m/s
Explanation:
At A kinetic energy is zero and potential energy=mgh=0.5*9.81*0.6=2.943 J
By conservation of energy.
KE+PE=Constant
At C PE=0.6 J
the KE=2.943-0.6=2.343 J
KE=0.5*m*v^2
v=√[KE/(0.5*m)]=3.06 m/s
Answer:
c. No. An equation may have consistent units but still be numerically invaid.
Explanation:
For an equation to be corrected, it should have consistent units and also be numerically correct.
Most equation are of the form;
(Actual quantity) = (dimensionless constant) × (dimensionally correct quantity)
From the above, without the dimensionless constant the equation would be numerically wrong.
For example; Kinetic energy equation.
KE = 0.5(mv^2)
Without the dimensionless constant '0.5' the equation would be dimensionally correct but numerically wrong.
Answer:
GE = ME - 
, which agrees with option C in your list.
Explanation:
The definition of Mechanical Energy (ME) of a system is the addition of the gravitational potential energy (GE) plus the kinetic energy (KE) of the system:
ME = GE + KE
Given that the KE is: ,
solving for GE in the formula above gives:
GE = ME - KE = ME - , which agrees with option C
Kinetic energy = 0.5 * m * v²
m mass
v velocity
If the velocity stays the same and the kinetic energy goes down by a factor of 2, the mass must go down by a factor of 2 also.
