Answer:
The linear momentum of a particle with mass m moving with velocity v is defined as
p = mv (7.1)
Linear momentum is a vector . When giving the linear momentum of a particle you must
specify its magnitude and direction. We can see from the definition that its units must be
kg·m
s
. Oddly enough, this combination of SI units does not have a commonly–used named so
we leave it as kg·m
s
!
The momentum of a particle is related to the net force on that particle in a simple way;
since the mass of a particle remains constant, if we take the time derivative of a particle’s
momentum we find
dp
dt = m
dv
dt = ma = Fnet
so that
Fnet =
dp
dt (7.2)
Answer:
0.5 , 54.5
Explanation:
for acceleration we should derivate the equation 2 times
x=3t³+t²/4
v=9t²+t/2
a=18t+1/2
a(0)=0.5
a(3)=54.5
Answer:
0.786 Hz, 1.572 Hz, 2.358 Hz, 3.144 Hz
Explanation:
The fundamental frequency of a standing wave on a string is given by
where
L is the length of the string
T is the tension in the string
is the mass per unit length
For the string in the problem,
L = 30.0 m
T = 20.0 N
Substituting into the equation, we find the fundamental frequency:
The next frequencies (harmonics) are given by
with n being an integer number and f being the fundamental frequency.
So we get:
<u>Answer</u>
3 Ohms
<u>Explanation</u>
when the resistors are in series, the resistance in the circuit increases. For example, if two resistors, R1 and R2 are in series, the combined resistance is R1+R2.
When connected in parallel, the total resistance is the reciprocal of (1/R1 + 1/R2)
In this case the resistors are in parallel.
Total resistance = (1/12 + 1/4)⁻¹
= (1/3)⁻¹
= 3 Ohms
Answer:
2.24 seconds
Explanation:
xf = xo + vo t + 1/2 at^2
45 = 0 + 15 t + 1/2 (4.5) t^2
2.25 t^2 + 15t - 45 = 0 Quadratic formula shows t = 2.24 seconds
