Question

A bicyclist steadily speeds up from rest to 9.00m/s during a 7.20s time interval. Determine all unknowns and answer the following questions. What is the magnitude of the bicyclist's acceleration? unit How far did the bicyclist travel during this time? unit​

Answer 1

Answer:

First, let us make some simplifications in notation. Taking the initial time to be zero, as if time is measured with a stopwatch, is a great simplification. Since elapsed time is

Δ

t

=

t

f

−

t

0

, taking

t

0

=

0

 means that

Δ

t

=

t

f

, the final time on the stopwatch. When initial time is taken to be zero, we use the subscript 0 to denote initial values of position and velocity. That is,

x

0

is the initial position and

v

0

is the initial velocity. We put no subscripts on the final values. That is,

t

is the final time,

x

is the final position, and

v

is the final velocity. This gives a simpler expression for elapsed time—now,

Δ

t

=

t

. It also simplifies the expression for displacement, which is now

Δ

x

=

x

−

x

0

. Also, it simplifies the expression for change in velocity, which is now

Δ

v

=

v

−

v

0

. To summarize, using the simplified notation, with the initial time taken to be zero,

Δ

t

=

t

Δ

x

=

x

−

x

0

Δ

v

=

v

−

v

0

 

}

Explanation: