Answer:
v = 2.18m/s
Explanation:
In order to calculate the speed of Betty and her dog you take into account the law of momentum conservation. The total momentum before Betty catches her dog must be equal to the total momentum after.
Then you have:
(1)
M: mass Betty = 40kg
m: mass of the dog = 15kg
v1o: initial speed of Betty = 3.0m/s
v2o: initial speed of the dog = 0 m/s
v: speed of both Betty and her dog = ?
You solve the equation (1) for v:
The speed fo both Betty and her dog is 2.18m/s
Answer:
C. 85%
Explanation:
A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantity of a hydrocarbon material is combusted inside the cylinder to produce 1 kJ of energy, and if the volume of the chamber then increases to 1.5 L, what percent of the fuel's energy was lost to friction and heat?
A. 15%
B. 30%
C. 85%
D. 100%
work done by the system will be
W=PdV
p=pressure
dV=change in volume
3tam will be changed to N/m^2
3*1.01*10^5
W=3.03*10^5*(1.5-1)
convert 0.5L to m^3
5*10^-4
W=3.03*10^5*5*10^-4
W=152J
therefore
to find the percentage used
152/1000*100
15%
100%-15%
85% uf the fuel's energy was lost to friction and heat
The equation you use is Ke = 1/2mv^2. when you plug in the numbers that are given you get Ke= 1/2(4)(2^2) which gives you a Kinetic Energy of 8
Answer:
0.5 m
14.00595
8 m/s, 0.0625 s
5.71314 m/s
Explanation:
k = Spring constant = 128 N/m
A = Amplitude
E = Energy in spring = 16 J
Energy in spring is given by
The amplitude is 0.5 m
Time period is given by
Number of oscillations is given by
The number of oscillations is 14.00595
For maximum speed
The maximum speed is 8 m/s
For a distance of 0.5 m which is the amplitude
The time taken would be 0.0625 s
The maximum kinetic energy is equal to the mechanical energy
At x = 0.35 m
The speed of the block is 5.71314 m/s
Answer:
<h2>1567.09 N/m</h2>
Explanation:
Step one:
given data
mass m=5kg
compression x= 3.13cm to m= 0.0313m
<em>According to Hooke's law, provided the elastic limit of an elastic material is not exceeded the extension e is directly proportional to the applied force</em>
F=ke
where
k= spring constant in N/m
e= extension/compression in
Step two:
assume g= 9.81m/s^2
F=mg
F=5*9.81
F=49.05N
substitute in the expression F=ke
49.05=k*0.0313
k=49.05/0.0313
k=1567.09 N/m
<u>The force constant (in N/m) of the spring is 1567.09 N/m</u>
