91影视

For Questions 1 through 3, interpret the position graph given in each

figure by writing a very short 鈥渟tory鈥� of what is happening. Be creative!

Have characters and situations! Simply saying that 鈥渁 car moves

100 meters to the right鈥� doesn鈥檛 qualify as a story. Your stories should

make specific reference to information you obtain from the graph, such

as distance moved or time elapsed.

A small child gives a plastic frog a big push at the bottom of a slippery 2.0-m-long, 1.0-m-high ramp, starting it with a speed of 5.0 m/s. What is the frog鈥檚 speed as it flies off the top of the ramp?

FIGURE EX2.31 shows the acceleration-versus-time graph of a particle moving along the x-axis. Its initial velocity is v0x = 8.0 m/s at t0 = 0 s. What is the particle鈥檚 velocity at t = 4.0 s?

FIGURE EX2.32 shows the acceleration graph for a particle that starts from rest at t = 0 s. What is the particle鈥檚 velocity at t = 6 s?

A particle moving along the x-axis has its position described by the function x = 12t 3 + 2t + 12 m, where t is in s. At t = 2 s what are the particle鈥檚 (a) position, (b) velocity, and (c) acceleration?

A particle moving along the x-axis has its velocity described by the function $v_x=2t^2$m/s, where t is in s. Its initial position is x0 = 1 m at t0 = 0 s. At t = 1 s what are the particle鈥檚 (a) position, (b) velocity, and (c) acceleration?

The position of a particle is given by the function x = 12t 3 - 9t 2 + 122 m, where t is in s. a. At what time or times is vx = 0 m/s? b. What are the particle鈥檚 position and its acceleration at this time(s)?

The position of a particle is given by the function $x=2t^3-6t^2+12$m, where t is in s. a. At what time does the particle reach its minimum velocity? What is ${\left(V_x\right)}_{min}$? b. At what time is the acceleration zero?

Particles A, B, and C move along the x-axis. Particle C has an initial velocity of 10 m/s. In FIGURE P2.37, the graph for A is a position-versus-time graph; the graph for B is a velocity-versus time graph; the graph for C is an acceleration-versus-time graph. Find each particle鈥檚 velocity at t = 7.0 s.

A block is suspended from a spring, pulled down, and released. The block鈥檚 position-versus-time graph is shown in FIGURE P2.38. a. At what times is the velocity zero? At what times is the velocity most positive? Most negative? b. Draw a reasonable velocity-versus-time graph.