Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the air

A) 0.50 times as long.

B) 1.41 times as long.

C) twice as long.

D) three times as long.

E) four times as long.

Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John jumps

A) 0.50 times as long.

B) 1.41 times as long.

C) twice as long.

D) three times as long.

E) four times as long.

Two objects are dropped from a bridge, an interval of 1.0 s apart. During the time that both objects continue to fall, their separation

A) increases.

B) decreases.

C) stays constant.

D) increases at first, but then stays constant.

E) decreases at first, but then stays constant.

From the edge of a roof top you toss a green ball upwards with initial velocity v0 and a blue ball downwards with the same initial velocity. When they reach the ground below,

A) the green ball will be moving faster than the blue ball.

B) the blue ball will be moving faster than the green ball.

C) the two balls will have the same speed.

**EXPERT ANSWER **

Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the air

A) 0.50 times as long.

B) 1.41 times as long.

C) twice as long.

D) three times as long.

E) four times as long.

**Answer :**C) twice as long.

Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John jumps

A) 0.50 times as long.

B) 1.41 times as long.

C) twice as long.

D) three times as long.

E) four times as long.

**Answer :**E) four times as long.

Two objects are dropped from a bridge, an interval of 1.0 s apart. During the time that both objects continue to fall, their separation

A) increases.

B) decreases.

C) stays constant.

D) increases at first, but then stays constant.

E) decreases at first, but then stays constant.

**Answer :**A) increases.

From the edge of a roof top you toss a green ball upwards with initial velocity v0 and a blue ball downwards with the same initial velocity. When they reach the ground below,

A) the green ball will be moving faster than the blue ball.

B) the blue ball will be moving faster than the green ball.

C) the two balls will have the same speed.

**Answer : **C) the two balls will have the same speed.