Reflection: you look in the mirror.
Refraction: You put a straw in a glass of water, and it looks like it broke.
Absorption: If you have a black sweater and you wear it out in the cold, the black sweater is going to hold in heat better than a lighter sweater because the black sweater absorbs light .
There are correlation and causation between the force of the finger and the movement of the books
Take a look at a simple reaction like the one below:
In this reaction some reactant A is turned into some product B. The rate of reaction can be represented by a decrease in concentration of A over time or as the increase of B over time. This is written:
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of
Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is
with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Answer:
769,048.28Joules
Explanation:
A parachutist of mass 56.0 kg jumps out of a balloon at a height of 1400 m and lands on the ground with a speed of 5.10 m/s. How much energy was lost to air friction during this bump
The energy lost due to friction is expressed using the formula;
Energy lost = Potential Energy + Kinetic Energy
Energy lost = mgh + 1/2mv²
m is the mass
g is the acceleration due to gravity
h is the height
v is the speed
Substitute the given values into the formula;
Energy lost = 56(9.8)(1400) + 1/2(56)(5.10)²
Energy lost = 768,320 + 728.28
Energy lost = 769,048.28Joules
<em>Hence the amount of energy that was lost to air friction during this jump is 769,048.28Joules</em>
