Answer:
Explanation: simple kinematics
we suppose that initially vo= 0 so if the skier moves 4s :
vf = vo +at = 0 + 3*4 = 12 m/s
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In 6 secs, the dog covers-
S=vt
8.9*6 = 53.4 m.
In the same time, the cat covers, 53.4-3.8 = 49.6 m.
Thus, speed of the cat, v= s/t,
= 49.6/6 = 8.267 m/s
Answer:
691200 J
Explanation:
From specific heat capacity,
ΔQ = cmΔt.................. Equation 1
Where ΔQ = increase in thermal energy, c = specific heat capacity of the body, m = mass of the man, Δt = rise in temperature.
Given: c = 3.6 kJ/kg.°C = 3600 J/kg.°C, m = 96 kg, Δt = 39-37 = 2 °C.
Substitute into equation 1
ΔQ = 3600×96×2
ΔQ = 691200 J.
Hence the change in the thermal energy of the body = 691200 J
Because field lines don’t all go in to the pole. The bottom half go outwards not inwards.