Answer:
o The result of a chemical change is a different composition; in a physical change, the composition remains the same.
Explanation:
In a chemical change, new kinds of matter are produced although the atoms are the same.
For physical changes, no new kinds of matter formed. Only the state of substances changes.
- Most chemical changes are usually irreversible
- Physical changes are reversible in most parts.
- Changes in state and form are salient characteristics of physical changes.
- When new products are formed from the reactants, it is an indicator of a chemical change.
Power is calculated as work per unit time, and work in turn is calculated as force multiplied by distance. In this case, the force required is equivalent to the weight of the barbell multiplied by acceleration due to gravity.
P = W/t = Fd/t = mgd/t = (200 kg)(9.81 m/s^2)(2 m)/2.2 s = 1783.64 Watts.
Answer:
U = 102.8 J (100 J to two significant digits)
Explanation:
potential energy converted = 20(9.8)(1.8) = 352.8 J
kinetic energy at base of track = ½(20)5.0² = 250 J
energy (work) of friction 352.8 - 250 = 102.8 J
Answer:
the distance traveled by the fish is 3648 m
Explanation:
In general, animals have a small period of acceleration, which we will despise after which they travel at a constant speed so we can use the kinematic equations in uniform motion
We reduce the units to System SI
t = 2 min (60s / 1 min) = 120 s
Calculate
V = x / t
x= V t
x = 30.4 120
x = 3648 m
This is the distance traveled by the fish
Answer:
1.6 ft/min
Explanation:
Since trough is 10 ft long and water is filled at the rate of 12ft3/min. We can calculate the rate of water filled with respect to area:
= 12 / 10 = 1.2ft2/min
As the water level rises, so does the water surface, or the bottom side of the isosceles triangles. In fact we can calculate the bottom side when the trough is half foot deep:
= 3 / 2 = 1.5 ft
The rate of change in water level would be the same as calculating the height of the isosceles triangles knowing its base
= 1.2 * 2 / 1.5 = 1.6 ft/min
