Objects absorb and reflect light differently depending on their physical characteristics, such as their shape or composition. Thanks to the reflection we can see the objects. Reflection can be defined as the change of direction of a wave, which, when in contact with the separation surface between two changing means, returns to the point where it originated. When the light illuminates the object, such as the tree, the rays of light will disperse in all directions allowing observation.
The correct answer is A. From every point on the surface of the tree, and in every direction
Answer:
which corresponds to the second option shown: "voltage times amperage"
Explanation:
The electric power is the work done to move a charge Q across a given difference of potential V per unit of time.
Since such electrical work is the product of the potential difference V times the charge that moves through that potential, and this work is to be calculated by the unit of time, we need to divide the product by time (t) which leads to the following final simple equation:
Notice that we replaced the quotient representing charge per unit of time (Q/t) by the actual current running through the circuit.
This corresponds to the second option shown in the question: "Voltage times amperage".
Answer:
(a) p = 3.4 kg-m/s (b) 37.78 N.
Explanation:
Mass of a basketball, m = 0.4 kg
Initial velocity of the ball, u = -5.7 m/s (as it comes down so it is negative)
It rebounds upward at a speed of 2.8 m/s (as it rebounds so positive)
(a) Change in momentum = final momentum - initial momentum
p = m(v-u)
p = 0.4 (2.8-(-5.7))
p = 3.4 kg-m/s
(b) Impulse = change in momentum
Ft = 3.4
We have, t = 0.09 s
Hence, this is the required solution.
Answer:
Explanation:
Here's what we know because it was given to us:
a = -9.8 m/s/s and
time = 3.32 seconds
Here's what we know because we rock physics:
v₀ = 0 (because the object was held still before it was dropped).
Here's the equation that ties all that info together in a single one-dimensional equation:
v = v₀ + at
Filling in and solving for v:
v = 0 + (-9.8)(3.32) and
v = -33m/s
The velocity is negative because the object is moving downwards and up is positive (but you knew that already too!)
B. five electrons
If you want an explanation, here it is.
The atomic number gives the number of protons. Protons which have a positive charge are balanced by an equal number of electrons in a neutral atom. Boron number 5 has five protons and therefore as a neutral atom also has five electrons.
