Aboy of mass 45 kg jumps off a wall 1.7m high.
he experiences a uniform acceleration of - 9.8 m/s^2when
his feet strike the ground, the rest of his body comes to
rest 0.12 s after.
a) calculate the time taken for the boy's feet to reach the
ground and the velocity with which his feet land.
b) calculate the force, impulse and change of momentum that
he experiences.
() find his stopping distance and say what this distance
physically represents. (assume that the ground is hand and
unyielding.
d) find the gravitational potential energy of the boy on the
wall and the kinetic energy just before he lands on the
ground.

answer:   you might love summer weather, but you don’t want it to feel like the sun is inside your car. but a hot car that just won’t seem to cool down might be a bigger of a problem than you think. your car relies on being at the right temperature.

explanation:

magnified images possible images can be real = projected onto a screen

laticia draws the diagram below to show earth’s magnetic field.

answer

the arrows to the right of earth should point up.

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.