Answer:
4*9 = 36 m/sec at 9 seconds. The average speed is (0 + 36)/2 = 18 .
Explanation:
You know how speed is how fast distance changes ?
Well, velocity is speed PLUS the direction of the motion,
and acceleration is how fast velocity changes.
Refer to the diagram shown below.
At A, the boy begins walking up the stairs.
At B, the boy is at the top of the slide. He has acquired PE (potential energy).
The value of the PE is
(50 kg)*(9.8 m/s²)*(11.5 m) = 5635 J
At C, the boy has KE (kinetic energy).
The value of the KE is
(1/2)*(50 kg)*(12 m/s)² = 3600 J
Energy is lost between B and C due to friction.
The lost energy is
5635 - 3600 = 2035 J
The distance traveled along the slide is 108 m.
If F = the average frictional force, then
(F N)*(108 m) = 2035 J
F = 18.84 N
Answers:
(a) The mechanical energy lost by sliding is 2035 J.
(b) The average frictional force is 18.84 N
Answer:
2475042
Explanation:
P = Pressure = [/tex]1\times 10^{-8}\ N/m^2[/tex]
V = Volume = 1 cm³
T = Temperature = 19.5 °C
R = Gas constant = 8.341 J/mol K
= Avogadro's number = 
n = Amount of substance
From ideal gas law we have

Number of atoms is given by

The number of atoms in this vacuum is 2475042