Medical movement for disabilities people
It really depends on what the bulb is being used for, since efficiency means how much of the output is USEFUL.
If the bulb is being used for light in a dark room, then it produces (8.2% x 21W) = 1.72 joules per second of light energy.
If the bulb is being used to keep a hamster cage or a fish tank warm, then the 8.2% is the useful part, and the light is the other (91.8% x 21W) = 19.28 joules per second.
The bigger the object the greater the gravitational pull, so the farther away the big object is its gravitational force begins to decrease. Refer to the picture for more explanation.
Explanation:
You are given the initial velocity, the displacement, and the acceleration. You're looking for the final velocity. So you use the equation:
v² = v₀² + 2aΔy
When you solve for v, you take the square root. Your calculator will return a positive answer, but there are actually two possible answers: positive and negative.
v = ±√(v₀² + 2aΔy)
You must use the physical context of the problem. If we take up to be the positive direction, then v must be negative, since the projectile is moving down.
From the information in the question, the velocity of the particle is 24 ms-1.
Let us recall that the velocity of a body is obtained as the first derivative of distance covered with respect to time. Hence;
ds/dt = v
Now, we have to differentiate (t^3- 3t^2 + 2)m with respect to t and we have;
d(t^3- 3t^2 + 2)m/dt = 3t^2 - 6t
Now at t= 4s, the velocity of the particle is;
3(4)^2 - 6(4) = 24 m/s
The acceleration of the particle is the second derivative of distance with respect to time;
d^2s/dt^2 = d^2 3t^2 - 6t/dt^2 = 6t
Substituting t = 4s
a = 24 ms-2
Learn more: brainly.com/question/24486060
