Answer:
0.56 m/s
Explanation:
The speed of the head at the end of the interval in each case is the area under the acceleration curve. Then the difference in speeds is the difference in areas.
We can find the area geometrically, using formulas for the area of a triangle and of a trapezoid.
A = 1/2bh . . . . area of a triangle
A = 1/2(b1 +b2)h . . . . area of a trapezoid
If h(t) is the acceleration at time t for a helmeted head, the area under that curve will be (in units of mm/s) ...
Vh = 1/2(h(3)·3) +1/2(h(3) +h(4))·1 +1/2(h(4) +h(6))·2 +1/2(h(6))·1
Vh = 1/2(4h(3) +3h(4) +3h(6)) = 1/2(4·40 +3·40 +3·80) = 260 . . . mm/s
If b(t) is the acceleration for a bare head, the area under that curve in the same units is ...
Vb = 1/2(b(2)·2 +1/2(b(2) +b(4))·2 +1/2(b(4) +b(6))·2 +1/2(b(6)·1)
Vb = 1/2(4b(2) +4b(4) +3b(6)) = 1/2(4·120 +4·140 +3·200) = 820 . . . mm/s
Then the difference in speed between the bare head and the helmeted head is ... (0.820 -0.260) m/s = 0.560 m/s
SI unit for mas is Kg and the SI unit of weight N for newton
Answer:C
Explanation:
Radar waves will be useful to examine the surface of the planet.
Radio waves are the shorter wavelength microwaves ranging approximately 1 cm.
Short wavelength causes large reflection from large objects. These waves are useful to detect smaller objects like water drops in the cloud.
They can penetrate clouds and that is why they are used in weather forecasting, air traffic control, etc.
Answer:
Asexual reproduction produces offspring that are genetically identical to the parent because the offspring are all clones of the original parent. During sexual reproduction the genetic material of two individuals is combined to produce genetically diverse offspring that differ from their parents.
Explanation:
At 60 mph. The 18-wheeler is moving slower, so its molecules have less kinetic energy.