# Describe the motion of the following objects if they are observed from the

stated frames of reference:

a. a person standing on a platform viewed from a train traveling north

b. a train traveling north viewed by a person standing on a platform

c. a ball dropped by a boy walking at a speed of 1 m/s viewed by the boy

d. a ball dropped by a boy walking 1 m/s as seen by a nearby viewer who

is stationary

show work !

Answers: 1

## Answers

Describe the motion of the following objects if they are observed from the stated frames of referenc...

answer: i think c

explanation:

1. The power in delivering the load is 13,230 Watts.

2. The power developed from a jumbo jet is 25 Mega Watts or Watts.

Explanation:

Power is the time rate at which work is done.

Useful Conversions:

1 horsepower (hp) = 550 ft.lb/s

1 hp =746 Watts

Formula for Power is:

equation 1

equation 2

where

is power, unit is in Watts (metric) or horsepower, hp (British system)

is work, unit is in Newton-meter (N.m) or Joules (J)

is velocity, unit is in m/s

is time, unit is in seconds

Formula for Work is:

where

is work done on a body, unit is in N.m or Joules

is force, unit is in Newtons (N)

is the distance, unit is in meters (m)

Formula for Force is:

where

is the force, unit is in Newtons (N)

is the mass, unit is in kg

is the acceleration due to gravity equal to 9.8

1. Solving for the power for problem #1 with the following given:

, , ,

a. Solve first for the force, we get:

b. Then, substitute the force to solve for work, we get:

c. Now, substitute the answer of work to the formula for power, we get:

2. Solving for power in problem #2 with the following given:

, ,

a. Solving the power using equation 2, we get:

or

or mega Watts

For more information about Power, just click on the following links:

* More example about power, work and force

* Relationship between power, work and energy

* Real life application for work, energy and power

#LetsStudy

Good Day

Problem:

a ball thrown straigjt upward. If it takes 4.25 seconds to reach the top of its path, what is its initial speed?

Given Data:

Vi (initial velocity) = ? unknown

Vf (final velocity) = 0 m/s (at top)

t (time) = 4.25 s

a (acceleration) = -9.8 m/s² (going up decelerating)

Solution:

We can solve the problem using the formula a = (Vf-Vi)/t

To solve for Vi, we can use - Vi = at Vf

- Vi = at Vf

- Vi = -9.8 m/s² × 4.25 s + 0 m/s

- Vi = - 41.65 m/s + 0 m/s

( - Vi = - 41.65 m/s) × -1

Vi = 41.65 m/s

Hope it helps=)

Initial Velocity is 41.65 m/s