Answer:
william h. seward secured the purchase of alaska from:
Explanation:
amount of work done is 5880 J
Given:
mass of object = 50kg
Final height = 20m
initial height = 8m
To Find:
amount of work done
Solution:
work is done when a force acts upon an object to cause a displacement. You can calculate the energy transferred, or work done, by multiplying the force by the distance moved in the direction of the force.
The work done by gravity is given by the formula,
W = mgh
W = 50 x 9.8 x ( 20-8)
= 5880 J
So the work done is 5880 J
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A, chemical bondings would yield a positive enthalpy change, thus endothermic.
An infant galaxy that is studied through the use of radio waves is called QUASAR.
Quasar are astronomical object, which have very high luminosity and they are found in the centers of some galaxies. Scientists believed that quasar are centers of distant galaxies. Radio waves is used to study quasar because they emit a huge amount of radio waves.
Answer:
(c) 10m/s
Explanation:
to find the speed of the waves you can use the following formula:

λ: wavelength of the wave
T: period
the wavelength is the distance between crests = 48m
the period is the time of a complete oscillation of the wave. In this case you have that the float takes 2.4 s to go from its highest to the lowest point. The period will be twice that time:
T = 2(2.4s)=4.8s
by replacing you obtain:

the answer is (c) 10m/s