Answer:
4.5 s, 324 ft
Explanation:
The object is projected upward with an initial velocity of

The equation that describes its height at time t is
(1)
where t, the time, is measured in seconds.
In order to find the time it takes for the object to reach the maximum height, we must find an expression for its velocity at time t, which can be found by calculating the derivative of the position, s(t):
(2)
At the maximum heigth, the vertical velocity is zero:
v(t) = 0
Substituting into the equation above, we find the corresponding time at which the object reaches the maximum height:

And by substituting this value into eq.(1), we also find the maximum height:

Given parameters:
Mass of the car = 1000kg
Unknown:
Height = ?
To find the heights for the different amount potential energy given, we need to understand what potential energy is.
Potential energy is the energy at rest due to the position of a body.
It is mathematically expressed as:
P.E = mgh
m is the mass
g is the acceleration due to gravity = 9.8m/s²
h is the height of the car
Now the unknown is h, height and we make it the subject of the expression to make for easy calculation.
h = 
<u>For 2.0 x 10³ J;</u>
h =
= 0.204m
<u>For 2.0 x 10⁵ J;</u>
h =
= 20.4m
<u>For 1.0kJ = 1 x 10³J; </u>
h =
= 0.102m
Answer:
W = 0
Explanation:
We are given with, a construction worker is carrying a load of 40 kg over his head and is walking at a constant velocity. He travels a distance of 50 m.
The work done by an object is given by :

F = ma
So,

m is mass
a is acceleration
d is displacement
The worker is moving with constant velocity, its acceleration will be 0. So, the work done by the worker is 0.
Answer:The specific heat capacity of water is 4,200 joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C.
Explanation:
Answer:
She will make the mass of the smiley face twice as massive in order to keep the mobile in perfect balance.
Explanation:
mass of an object is directly proportional to the cube of its length. In this case the length is constant, the mass will also be constant for the smiley face, so that the mobile will be kept in perfect balance.
Therefore, If Anya decides to make the star twice as massive, and not change the length of any crossbar or the location of any object, she will make the mass of the smiley face twice as massive in order to keep the mobile in perfect balance.