A 70-kg swimmer dives horizontally off a 500-kg raft. The diver's speed immediately after leaving the raft is 6.0 m/s. A micro-sensor system attached to the edge of the raft measures the time interval during which the diver applies an impulse to the raft just prior to leaving the raft surface. If the time interval is read as 0.25 s, what is the magnitude of the average horizontal force by diver on the raft?
a. 110 N
b. 420 N
c. 2 000 N
d. 1 700 N
e. 24 N
[Ques. 2] The units of impulse are equivalent to:
a. those of energy.
b. N/m.
c. kg/m/s.
d. those of force.
[Ques. 3] A ball with original momentum +7.0 kg/m/s hits a wall and bounces straight back without losing any kinetic energy. The change in momentum of the ball is:
a. 0.
b. 14 kg/m/s.
c. 7.0 kg/m/s.
d. 14 kg/m/s.
e. 7.0 kg/m/s.
[Ques. 4] The dimensional equivalence of the quantity momentum in terms of the fundamental quantities (mass, length, time) is:
a. MLT1.
b. ML2T2.
c. MLT.
d. MLT2.
[Ques. 5] The impulse experienced by a body is equivalent to its change in:
a. velocity.
b. kinetic energy.
c. momentum.
d. None of the above choices are valid.
[Ques. 6] A valid unit for momentum is which of the following?
a. kg/m/s2
b. kg/m2
c. kg/m/s
d. N/m
[Ques. 7] The dimensional equivalent of the quantity impulse in terms of the fundamental quantities (mass, length, time) is which of the following?
a. MLT1
b. ML2T2
c. MLT
d. MLT2
[Ques. 8] An asteroid has a perihelion (the orbit's closest approach to the Sun) of 1.5 AU and a period of revolution of 8.0 yr. What is its greatest distance from the Sun (its aphelion)?
a. 8.0 AU
b. 6.5 AU
c. 4.0 AU
d. 2.5 AU
[Ques. 9] At an altitude of 5 times the radius of the Earth, the acceleration due to gravity is
a. g/5.
b. 5g.
c. g/25.
d. not given.
[Ques. 10] Geosynchronous satellites orbit the Earth at a distance of 42 000 km from the Earth's center. Their angular speed at this height is the same as the rotation rate of the Earth, so they appear stationary at certain locations in the sky. What is the force acting on a 1 500-kg satellite at this height?
a. 85.0 N
b. 333 N
c. 404 N
d. 457 N
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