Problem

Two skiers, Annie and Jack, start skiing from rest at different points on a hill at the sa...

Two skiers, Annie and Jack, start skiing from rest at different points on a hill at the same time. Jack, with mass 88.0 kg, skis from the top of the hill down a steeper section with an angle of inclination of 35.0°. Annie, with mass 64.0 kg, starts from a lower point and skis a less steep section, with an angle of inclination of 20.0°. The length of the steeper section is 100. m. Determine the acceleration, velocity, and position vectors of the combined center of mass for Annie and Jack as a function of time before Jack reaches the less steep section.

Step-by-Step Solution

Solution 1

THINK:

Determine the acceleration, velocity and position vectors of the combined center of mass for two persons as a function of time before one person reaches the less steep section.

RESEARCH:

The poison vector of the combined center of mass for Annie and Jack is

…… (1)

The velocity vector of the combined center of mass for Annie and Jack is

…… (2)

The acceleration vector of the combined center of mass for Annie and Jack is

…… (3)

SIMPLIFY:

When an object is slides down on an incline plane, the acceleration given by

Acceleration of Annie in axis direction is

Acceleration of Jack in axis direction is

Acceleration of Annie in axis direction is

…… (4)

Acceleration of Jack in axis direction is

…… (5)

Then

…… (6)

…… (7)

Since each skier starts from rest, the initial speeds of both are zero.

From the equation of motion, , since

In axis direction,

…… (8)

And

…… (9)

By substituting the equation (8) and (9), in the equation (2), we get

…… (10)

Similarly,

…… (11)

From the equation of motion,

The position vectors of Annie and Jack are:

In axis direction:

…… (12)

Substitute the value of in the equation (12), we get

…… (13)

From the diagram,

Similarly,

In the axis direction,

…… (14)

And

…… (15)

From the diagram,

From equation (1), (14) and (15), we get

……. (16)

……. (17)

CALCULATE:

Given,

Mass of the Jack is

Steeper section with an angle of inclination of

Mass of the Annie is

Angle of inclination for Annie is

Length of the steeper section is

By substituting all known values in the equations (7) and (8), we get

The component acceleration of the center of mass for Annie and Jack is

The component acceleration of the center of mass for Annie and Jack is

By substituting all known values in the equations (10) and (11), we get

The component velocity of the center of mass for Annie and Jack is

The component velocity of the center of mass for Annie and Jack is

By substituting all known values in the equations (16) and (17), we get

The component poison of the center of mass for Annie and Jack is

The component velocity of the center of mass for Annie and Jack is

Add your Solution
Textbook Solutions and Answers Search
ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT