Sally's average speed is <u>35.3 mi/h.</u>
Average speed of a body is the total distance traveled in the given time interval.
Express the distance d traveled in miles.

Express the time t traveled in hours.

Calculate the average speed v.

Her average speed is 35.3 mi/h, which is less than the speed limit of 65 mi/h.
However, the average speed of an object is different from its instantaneous speed. It could be possible that at the time when the officer apprehended her, Sally could have been travelling at a speed greater than the prescribed speed limit, which would have prompted the officer to issue a speeding ticket to her.
Thus, the average speed of a person cannot be considered as a bench mark for speeding offences, since her instantaneous speed could have been higher than the speeding limit and yet she could have had an average speed less than the speeding limit.
Answer:
A metalloid is used because it is a semiconductor and can become more conductive when more light shines on it
Explanation:
The material used in a solar panel is a metalloid. It can often become conductive when more light shines on it.
Metalloids have properties that straddles between those of metals and non-metals.
In essence, they can be conductive or not under certain conditions.
The most important property they exhibit is that they can become more conductive when more light shines on them. This way more electrons are produced.
Answer:
Explanation:
Given
Initial reading on scale =40 N
So, we can conclude that weight of the sack is 40 N
After this a 10 N force is applied upward on the sack such that the net force becomes (40-10) N downward (because downward force is more)
This net downward force is the resultant of earth graviational pull and the applied upward force.
So, this downward force acts on the machine which inturn applies an upaward force of same magnitude called Normal reaction.
This situation can be diagramatically represented by figure given below
Answer: a) 19.21m b) 3.92secs
Explanation:
a) Maximum height reached by the object is the height reached by an object before falling freely under gravity.
Maximum height = U²/2g
U is the initial velocity = 19.6m/s
g is acceleration due to gravity = 10m/s²
Maximum Height = 19.6²/2(10)
H = 19.21m
b) The time elapsed before the stone hits the ground is the time of flight T= 2U/g
T= 2(19.6)/10
T = 39.2/10
Time elapsed is 3.92secs