# Physics

A track star in the long jump goes into the jump at 12 m/s and launches herself at 20.0° above the horizontal. How long is she in the air before returning to Earth? (g = 9.81 m/s2)

1. 👍
2. 👎
3. 👁
1. Vo = 12m/s[20o]
Xo = 12*cos20 = 11.28 m/s.
Yo = 12*sin20 = 4.10 m/s.

Y = Yo + g*Tr = 0 @ max. ht.
4.10 - 9.8Tr = 0
-9.8Tr = -4.10
Tr = 0.419 s. = Rise time.

Tf = Tr = 0.419 s.

T = Tr + Tf = 0.419 + 0.419 = 0.838 s.=
Time in air.

1. 👍
2. 👎
2. 13m

1. 👍
2. 👎
3. superb

1. 👍
2. 👎

## Similar Questions

1. ### Algebra

The function y = –0.296x^2 + 2.7x models the length x and height y that your sister's pet rabbit can jump, in centimeters. How high does the rabbit jump? One the rabbit reaches the ground what is the total length of the jump? I

2. ### intro to physics

an athlete executing a long jump leaves the ground at a 28 degree angle and lands 7.6 m away. part a )what was the takeoff speed ? part b) if this speed were increased by just 8.0% , how much longer would the jump be ? for part a)

3. ### science

On average, froghopper insects have a mass of 12.3 mg and jump to a height of 428 mm. The takeoff velocity is achieved as the little critter flexes its leg over a distance of approximately 2.0 mm. Assume a vertical jump with

4. ### Math

Sarah competes in a long jump competition. Her first jump is 4.25m. Her best jump is 12% more than this. However, her best jump is 15% lower than the winning jump. Work out the length of the winning jump.

1. ### AP physics

Suppose a Chinook salmon needs to jump a waterfall that is 1.50 m high. If the fish starts from a distance 1.00 m from the base of the ledge over which the waterfall flows, find the x- and y-components of the initial velocity the

2. ### Physics

An athlete competing in long jump leaves the ground with a speed of 9.14 m/s at an angle of 35 degrees above the horizontal. What is the length of the athlete's jump?

3. ### Physics

At a track and field meet, the best long jump is measured as 8.30 m. The jumper took off at an angle of 31 ° to the horizontal. What was the jumper’s initial speed?

4. ### physics

At the 2004 Olympic Games in Athens, Dwight Phillips won the gold medal in men’s long jump with a jump of 8.59 m. If the angle of his jump was 23°, what was his takeoff speed? (Treat the jumper as an object; ignore that his

1. ### science

If it takes leaping Louie five minutes to jump three blocks how long will it take for him to jump 15 blocks?

2. ### physics

a 70 kg astronaut is loaded so heavily that he can jump only to a height of 10 cm on earth.how far can he jump on the moon?

3. ### physics

In Mostar, Bosnia, the ultimate test of a young man's courage once was to jump off a 400 year old bridge into the River Neretva, 23 m below the bridge. (a) How long did the jump last? (b) How fast was the diver traveling upon

4. ### physics

An athlete performing a long jump leaves the ground at a 27.1∘ angle and lands 7.72m away 1.What was the takeoff speed? 2.If this speed were increased by just 5.0%, how much longer would the jump be?