91影视

A basketball has a mass of 570g. Heading straight downward, in the y-direction, it hits the floor with the speed of 5 m/s and rebounds straight up with nearly the same speed. What was the momentum change $鈭�\stackrel{鈬赌}{p}$?

A basketball has a mass of 570 g. Moving to the right and heading downward at an angle of 30 to the vertical, it hits the floor with the speed of 5 m/s and bounces up with nearly the same speed, again moving to the right an angle of 30 degree to the vertical. What was the momentum change$鈭�\stackrel{鈬赌}{p}$?

The first stage of giant Saturn V rocket reached a speed of 2300 m/s at 170 s after lift-off.

(a) What was the average acceleration in m/s/s?

(b) The acceleration of a falling object if air resistance is negligible is 9.8 m/s/s, called 鈥渙ne g鈥�. What was the average acceleration in g鈥檚?

What is the velocity of aobject when its momentum is?

What is the velocity of a 3 kg object when its momentum is ?

A 1500 kg car located at $<300,0,0>\mathbf{m}$ has a momentum of $<45000,0,0>\mathbf{kg}\mathbf{}\mathbf{m}\mathbf{/}\mathbf{s}$ . What is its location 10 s later?

9 An ice hockey puck of mass 170 g enters the goal with a momentum of 鉄�0, 0, 鈭�6.3鉄� kg m/s, crossing the goal line at location 鉄�0, 0,鈭�26鉄� m relative to an origin in the center of the rink. The puck had been hit by a player 0.4 s before reaching the goal. What was the location of the puck when it was hit by the player, assuming negligible friction between the puck and the ice? (Note that the ice surface lies in the xz plane.)

(a) Consider the vectors ${\stackrel{鈫�}{r}}_1$and ${\stackrel{鈫�}{r}}_2$represented by arrows in Figure 1.20. Are these two vectors equal? (b) If ,and $\stackrel{鈫�}{c}=\stackrel{鈫�}{a}$, what is the unit vector $\hat{\mathrm{c}}$in the direction of $\stackrel{鈫�}{\mathrm{c}}$?

Consider the vectors $\stackrel{鈫�}{{\mathrm{r}}_1}$and $\stackrel{鈫�}{{\mathrm{r}}_2}$represented by arrows in Figure 1.20. Are these two vectors equal? (b) If $\stackrel{鈫�}{a}=<400,200-100>m/s^2$,and $\stackrel{鈫�}{c}=\stackrel{鈫�}{a}$, what is the unit vector $\hat{c}$in the direction of $\hat{c}$?

Figure 1.20

A space probe of mass 400 kg drifts past location with momentum . Assuming the momentum of the probe does not change, what will be its position 2 minutes later?