Answer:
Explanation:
A mass of 700 kg will exert a force of
700 x 9.8
= 6860 N.
Amount of compression x = 4 cm
= 4 x 10⁻² m
Force constant K = force of compression / compression
= 6860 / 4 x 10⁻²
= 1715 x 10² Nm⁻¹.
Let us take compression of r at any moment
Restoring force by spring
= k r
Force required to compress = kr
Let it is compressed by small length dr during which force will remain constant.
Work done
dW = Force x displacement
= -kr -dr
= kr dr
Work done to compress by length d
for it r ranges from 0 to -d
Integrating on both sides
W =
= [ kr²/2]₀^-4
= 1/2 kX16X10⁻⁴
= .5 x 1715 x 10² x 16 x 10⁻⁴
= 137.20 J
A) change in ht after 180m = 180 * sin(4-deg.) = 12.56m
net work done by gravity on the cyclist = mass * gravity * height diff.
= 85 * 9.8 * 12.56
= 10470J
= 10.5kJ
B) Kinetic energy = 1/2 * mass * vel.^2 = work done by gravity = 10470J
vel.^2 = 10470 * 2 / 85 = 246.4
vel. = 15.7m/s
Answer:
Explanation:
Momentum is the mass of a moving body times its velocity. It can be transferred from one object to another
Ptolemy believed in the theory that the earth was the center of the universe (geocentric) and it is not moving in the center while Copernicus later proposed otherwise, in his heliocentric theory he believed that the sun was the center of the universe but it was not moving. Both theories were influenced by their observation of how the light shade from the sun changes during the day, and also through observation of other celestial bodies whose light intensity changes which made them arrived to the conclusion that they are not equidistant nor stationary with respect to earth.