We use a fundamental kinematic equation as follows:
V = Vo + g*t.
<span>Tr = (V-Vo)/g = (0-10)/-10 = 1 s. = </span><span>time to reach max. height </span>
<span>Tf = Tr = 1 s. = Fall time or time to fall back to edge of bldg. </span>
<span>3-Tr-Tf = 3-1-1 = 1 s. Below edge of bldg. </span>
<span>d = Vo*t + 0.5g*t^2. </span>
<span>d = 10*1 + 5*1^2 = 15 m. <---- OPTION C</span>
Answer:
This means that the kinetic energy of second object is 48times that of the first object
Explanation:
Kinetic energy is the energy possessed by a body by virtue of its motion e.g motion of an accelerating car. Mathematically,
Kinetic energy = 1/2mv² where;
m is the mass of the object
v is the velocity of the object
If Object 1 of mass m moves with speed v in the positive direction, its kinetic energy will be expressed as;
K1 = 1/2mv²
For Object 2 of mass 3m moving with speed 4v in the negative x-direction, its kinetic energy can be expressed as;
K2 = 1/2(3m)(4v)²
K2 = 1/2(3m)(16v²)
K2 = (3m)(8v²)
K2 = 24mv²
To compare the kinetic energy of both bodies, we will take the ratio of K2:K1 to have;
K2/K1 = 24mv²/(1/2)mv²
K2/K1 = 24/(1/2)
K2/K1 = 48
K2 = 48K1
This means that the kinetic energy of second object is 48times that of the first object and moving in the negative x direction since the body of mass 3m initially moves in the negative x direction.
Answer:
solution:
to find the speed of a jogger use the following relation:
V
=
d
x
/d
t
=
7.5
×m
i
/
h
r
...........................(
1
)
in Above equation in x and t. Separating the variables and integrating,
∫
d
x
/7.5
×=
∫
d
t
+
C
or
−
4.7619
=
t
+
C
Here C =constant of integration.
x
=
0 at t
=
0
, we get: C
=
−
4.7619
now we have the relation to find the position and time for the jogger as:
−
4.7619 =
t
−
4.7619
.
.
.
.
.
.
.
.
.
(
2
)
Here
x is measured in miles and t in hours.
(a) To find the distance the jogger has run in 1 hr, we set t=1 in equation (2),
to get:
= −
4.7619
=
1
−
4.7619
= −
3.7619
or x
=
7.15
m
i
l
e
s
(b) To find the jogger's acceleration in m
i
l
/
differentiate
equation (1) with respect to time.
we have to eliminate x from the equation (1) using equation (2).
Eliminating x we get:
v
=
7.5×
Now differentiating above equation w.r.t time we get:
a
=
d
v/
d
t
=
−
0.675
/
At
t
=
0
the joggers acceleration is :
a
=
−
0.675
m
i
l
/
=
−
4.34
×
f
t
/
(c) required time for the jogger to run 6 miles is obtained by setting
x
=
6 in equation (2). We get:
−
4.7619
(
1
−
(
0.04
×
6 )
)^
7
/
10=
t
−
4.7619
or
t
=
0.832
h
r
s
Answer:
it is 2.2 m
Explanation:
because he goes back 2.2 m so 4.4 minus 2.2 equals 2.2
Around 70-72% of earth’s surface is covered in water (most of it is salt water).
Hope this helps.
