Answer:
True.
Explanation:
If the sum of the external forces on an object is zero, then the sum of the external torques on it must also be zero.
The net external force and the net external torque acting on the object have to be zero for an object to be in mechanical equilibrium.
Hence, the given statement is true.
The quantity work has to do with a force causing a displacement. Work has nothing to do with the amount of time that this force acts to cause the displacement. Sometimes, the work is done very quickly and other times the work is done rather slowly. For example, a rock climber takes an abnormally long time to elevate her body up a few meters along the side of a cliff. On the other hand, a trail hiker (who selects the easier path up the mountain) might elevate her body a few meters in a short amount of time. The two people might do the same amount of work, yet the hiker does the work in considerably less time than the rock climber. The quantity that has to do with the rate at which a certain amount of work is done is known as the power. The hiker has a greater power rating than the rock climber.
Power is the rate at which work is done. It is the work/time ratio. Mathematically, it is computed using the following equation.
Power = Work / time
or
P = W / t
Answer:
3 seconds
Explanation:
Since h(t) represents the height and t represents the time, we can set the equation equal to 150 to find t.
-16t^2+96t+6=150
Subtract 150 from both sides to set the equation equal to 0, to find the solutions.
-16t^2+96t-144=0
Factor out -16, because all of the terms are divisible by it.
-16(t^2+6t+9)=0
Now we can focus on the terms inside the parenthesis and factor it again.
t^2-6t+9=0
We need to find two value that can be multiplied to get 9 and added to get -6.
-3 and -3 works.
Thus, we get (x-3)(x-3).
Now solve for 0.
x-3=0
x=3
The object reaches its maximum height after 3 seconds.
Answer:
λ = 65.6 pm
Explanation:
Given that
λo = 65 pm
The initial energy of the electron
Now by putting the values
Eo=19.06 KeV
Given that kinetic energy KE= 0.84 KeV
Therefore the final energy
E= Eo - KE
E = 19.06 - 0.84 KeV
E= 18.22 KeV
The wavelength λ can be find as
λ = 6.56 x 10⁻¹¹ m
λ = 65.6 pm
