Astronomers believe some stars are moving away from earth by measuring the extent to which their light is “stretched” into the red part of the color spectrum, representing the lower frequencies on that spectrum.
In short, stars moving away from earth are “red-shift”, while if they were moving towards the earth they would take on a “blue-shift”.
All of the electromagnetic energy radiated from the sun (and from
other stars) is the product of nuclear fusion in its core.
Answer:
She can swing 1.0 m high.
Explanation:
Hi there!
The mechanical energy of Jane (ME) can be calculated by adding her gravitational potential (PE) plus her kinetic energy (KE).
The kinetic energy is calculated as follows:
KE = 1/2 · m · v²
And the potential energy:
PE = m · g · h
Where:
m = mass of Jane.
v = velocity.
g = acceleration due to gravity (9.8 m/s²).
h = height.
Then:
ME = KE + PE
Initially, Jane is running on the surface on which we assume that the gravitational potential energy of Jane is zero (the height is zero). Then:
ME = KE + PE (PE = 0)
ME = KE
ME = 1/2 · m · (4.5 m/s)²
ME = m · 10.125 m²/s²
When Jane reaches the maximum height, its velocity is zero (all the kinetic energy was converted into potential energy). Then, the mechanical energy will be:
ME = KE + PE (KE = 0)
ME = PE
ME = m · 9.8 m/s² · h
Then, equallizing both expressions of ME and solving for h:
m · 10.125 m²/s² = m · 9.8 m/s² · h
10.125 m²/s² / 9.8 m/s² = h
h = 1.0 m
She can swing 1.0 m high (if we neglect dissipative forces such as air resistance).
I have absolutely no clue
F = force applied to hold the weight of the bowling ball = weight of the bowling ball = 75 N
d = distance through which the bowling ball is moved horizontally = 10 meter
θ = angle between the force in vertically upward direction and displacement in horizontal direction = 90
W = work done on the bowling ball
work done on the bowling ball is given as
W = F d Cosθ
inserting the values
W = (75) (10) Cos90
W = (75) (10) (0)
W = 0 J
