Question

In a relay race, each contestant runs a distance 26.0 m while carrying an egg balanced on a spoon, turns around, and comes back to the starting point. Edith runs the first distance 26.0 m in a time t1 = 20.7 s . On the return trip she is more confident and takes only time t2 = 14.8 s .
a. What is the magnitude of her average velocity for the first distance 25.3 m ?
b. What is the magnitude of her average velocity for the return trip?
c. What is her average velocity for the entire round trip?
d. What is her average speed for the round trip?

Answer 1

Answer:

1.22 m/s

1.76 m/s

0

1.46 m/s

Explanation:

*in the first part i have taken 26 m as in the part above it is mentioned distance is 26 m.

$s_1$ = Displacement of the first run = 26 m

$s_2$ = Displacement of the second run = 26 m

$t_1$ = Time taken on the first run = 20.7 s

$t_2$ = Time taken on the second run = 14.8 s

Velocity is given by

$v_1=\dfrac{s_1}{t_1}\\\Rightarrow v_1=\dfrac{26}{20.7}\\\Rightarrow v_1=1.26\ \text{m/s}$

Average velocity of the first run is 1.22 m/s

$v_2=\dfrac{s_2}{t_2}\\\Rightarrow v_2=\dfrac{26}{14.8}\\\Rightarrow v_1=1.76\ \text{m/s}$

Average velocity of the first run is 1.76 m/s

Displacement for the round trip is 0 as she started and ended at the same point so her average velocity for the round trip is 0 m/s.

Average speed is given by

$s=\dfrac{\text{Total distance}}{\text{Total time}}\\\Rightarrow s=\dfrac{26+26}{20.7+14.8}\\\Rightarrow s=1.46\ \text{m/s}$

The average speed for the round trip is 1.46 m/s.