Average speed = (total distance) / (total time)
First segment:
15 m/s for 10 sec; distance covered = (15 x 10) = 150 m
Second segment:
20 m/s for 20 sec; distance covered = (20 x 20) = 400 m
Third segment:
30 m/s for 15 sec; distrance covered = (30 x 15) = 450 m
Total time = (10s + 20s + 15s) = 45 sec
Total distance = (150m + 400m + 450m) = 1,000 m (1 km)
<em>Average speed</em> = (1,000 m) / (45 sec) = <em>22.22 m/s</em>
Answer:
What do you mean ? what are you talking about?
The answer is d
F=ma. so by substituting we find that a=4
and a=vi-vf/t
by substiting we find vf=8
so the difference is vf-vi = 8m/s
Answer:
(1) Exercise should be painful in order for it to be beneficial. FALSE
(2) Proper progression involves a gradual increase in the level of exercise. TRUE
(3) Exercising on a regular, consistent basis provides you with the best results. TRUE
Explanation:
(1) It is a false statement because whenever we do exercise, it should not be painful, it should be comfortable to some extent for a person, if it will be painful then it means one cant get the true and genuine benefit from the exercise.
(2) It is very much true because one must keep on increasing the level of his/her exercise gradually with the passage of time, it will make his/her body synchronized with the exercise properly.
(3) It is also a true statement because, one must use variety of exercises in his/her workout session targeting different muscles and different areas and parts of the body to make exercise really beneficial.
Answer:
No the resistance of a given circuit does not remain constant if the temperature of the circuit changes.
Explanation:
The resistance of any resistor used in a circuit depends upon the temperature of that resistor. This can be mathematically represented as follows
Where,
R(t) is resistance of any resistor at temperature t
is the resistance of the resistor at time of fabrication
α is temperature coefficient of resistivity it's value is different for different materials
This change in the resistance is the cumulative effect of:
1) Variation of resistivity with temperature
2) Change in dimensions of the resistor with change in temperature