QUESTION 4
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4.1 A passenger plane accelerated from rest down a runway at a constant
acceleration of 2.5 m.s- 2.
(i) Determine the position and velocity of the plane 8 seconds after it
starts to move.
(3)
(ii) If the speed of 45 m/s is required for take-off, what is the minimum
length of runway required?
(2)
4.2 A spacecraft of mass 300 kg land on the moon. Calculate the moon's
gravitational acceleration, g, on the spacecraft. [Take mass of moon= 7.5 x
1022 kg, radius of the moon= 1.6 x 10 6 m, G = 6.67 x 10 - 11 Nm 2 kg-2]. (3)
4.3 A rocket of mass 150 kg is launched on planet Jupiter's surface into space.
Calculate the
(i) energy required to overcome the gravitational force of Jupiter.
(3)
(ii) velocity of rocket upon launching.
(2)
4.4 A CD starts from rest and accelerates to an angular frequency of 12.5 rev/s.
Determine the disc's average period T and centripetal velocity Ve of the edge
of the a disc when the radius is 3.5 x 10-3 m.
(2)
QUESTION 5
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5.1 Explain the terms adhesion and cohesion.
(2)
5.2 Suppose that a huge tank 50m high and filled with water is open to the
atmosphere and is hit with a stray bullet. The bullet pierces one side of the tank
allowing water to flow out. The hole is 2m above the ground. If the hole is so
small in comparison with the size of the tank. How quickly will the water flow?
Consider acceleration due to gravity to 9.8 m/s2
(6)
5.3 Determine the density of a sphere material, given that it has a radius of 8.2 mm
with mass of 200 g.
(4)
5.4 During the time when a man had flu, he ran a fever of 7.0°C above normal.
His body temperature was 44.0°C instead of the normal 37.0°C. Assuming
that the man has a mass of 40 kg and that the human body is mostly water,
how much heat is required to raise his temperature? [Take specific heat
capacity of liquid as, c = 4186 J / kg.0 C]
(3)
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