A ball is projected upward at time t = 0 s, from a point on a flat roof 90 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground
The initial velocity of the ball is Consider all quantities as positive in the upward direction. The vertical velocity of the ball when it is above the ground is closest to A) -81 m/s.
B) -64 m/s.
C) -48 m/s.
D) -32 m/s.
E) -97 m/s.
A
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A weight of mass m is at rest at O when suspended from a spring, as shown. When it is pulled down and released, it oscillates between positions A and B. Which statement about the system consisting of the spring and the mass is correct?
A. The gravitational potential energy of the system is greatest at A. B. The elastic potential energy of the system is greatest at O. C. The rate of change of momentum has its greatest magnitude at A and B. D. The rate of change of gravitational potential energy is smallest at O. E. The rate of change of gravitational potential energy has its greatest magnitude at A and B.
A paperclip with the density of a neutron star would weigh (on the Earth)
A) more than the Earth. B) more than Mt. Everest. C) a few tons. D) about the same as a regular paperclip. E) more than the Moon.
Absolute visual magnitude is the:
A) apparent magnitude of a star observed from Earth. B) luminosity of a star observed from a distance of 1000 pc. C) apparent magnitude of a star observed from a distance of 10 pc. D) luminosity of a star observed from Earth.
At a depth of about 1030 m in the sea, the pressure has increased by 100 atmospheres (to 1.0 × 107 N/m2). By how much has 1.0 m3 of water been compressed by this pressure? The bulk modulus of water is 2.3 × 109 N/m2
A) 2.3 × 10-3 m3 B) 3.3 × 10-3 m3 C) 4.3 × 10-3 m3 D) 5.3 × 10-3 m3 E) 6.3 × 10-3 m3