Refer to the diagram shown below.
Assume that
(a) The piano rolls down on frictionless wheels,
(b) Wind resistance is negligible.
The distance along the ramp is
d = (1.3 m)/sin(22°) = 3.4703 m
The component of the piano's weight along the ramp is
mg sin(22°)
If the acceleration down the ramp is a, then
ma = mg sin(22°)
a = g sin(22°) = (9.8 m/s²) sin(22°) = 3.671 m/s²
The time, t, to travel down the ramp from rest is given by
(3.4703 m) = 0.5*(3.671 m/s²)*(t s)²
t² = 3.4703/1.8355 = 1.8907
t = 1.375 s
Answer: 1.375 s
B) atmosphere pressure, i believe
Answer:
1) It expresses the rate (top speed) at which it can move with time.
2) P = 20 W
3) h = 18 km
Explanation:
1) Power is the rate of transfer of energy.
⇒ Power = ![\frac{Energy(or workdone)}{Time}](https://tex.z-dn.net/?f=%5Cfrac%7BEnergy%28or%20workdone%29%7D%7BTime%7D)
i.e P = ![\frac{E}{t}](https://tex.z-dn.net/?f=%5Cfrac%7BE%7D%7Bt%7D)
Thus a car's engine power is 44000W implies that the engine of the car can propel the car at this rate. This expresses the rate (top speed) at which it can move with time.
2) m = 400g = 0.4 kg
t = 20 s
h = 100m
g = 10 m/![s^{2}](https://tex.z-dn.net/?f=s%5E%7B2%7D)
P = ![\frac{mgh}{t}](https://tex.z-dn.net/?f=%5Cfrac%7Bmgh%7D%7Bt%7D)
= ![\frac{0.4*10*100}{20}](https://tex.z-dn.net/?f=%5Cfrac%7B0.4%2A10%2A100%7D%7B20%7D)
= ![\frac{400}{20}](https://tex.z-dn.net/?f=%5Cfrac%7B400%7D%7B20%7D)
P = 20 W
3) u = 600 m/s
g = 10 m/![s^{2}](https://tex.z-dn.net/?f=s%5E%7B2%7D)
From the third equation of free fall,
=
- 2gh
V is the final velocity, U is the initial velocity, h is the height.
0 =
- 2 x 10 x h
0 = 360000 - 20h
20h = 360000
h = ![\frac{360000}{20}](https://tex.z-dn.net/?f=%5Cfrac%7B360000%7D%7B20%7D)
= 18000
h = 18 km
The maximum height of the bullet would be 18 km.
Thermal energy is an example of kinetic energy , due to motion of particles .