Answer:
Explanation:
initial velocity, u = 0
final velocity, v = 60 mph = 26.8 m/s
time t = 10 s
Let a be the acceleration and s be he distance traveled.
Use first equation of motion
v = u + a t
26.8 = 0 + a x 10
a = 2.68 m/s
Use second equation of motion
s = ut + 1/2 at²
s = 0 + 0.5 x 2.68 x 10 x 10
s = 134 m
As, 1 m = 3.28 ft
So, s = 134 x 3.28 ft
s = 439.6 ft
Explanation:
First, we need to determine the distance traveled by the car in the first 30 minutes,
.
Notice that the unit measurement for speed, in this case, is km/hr. Thus, a unit conversion of from minutes into hours is required before proceeding with the calculation, as shown below

Now, it is known that the car traveled 40 km for the first 30 minutes. Hence, the remaining distance,
, in which the driver reduces the speed to 40km/hr is
.
Subsequently, we would also like to know the time taken for the car to reach its destination, denoted by
.
.
Finally, with all the required values at hand, the average speed of the car for the entire trip is calculated as the ratio of the change in distance over the change in time.

Therefore, the average speed of the car is 50 km/hr.
The correct answer would be True!

As per as my knowledge
The speed of a wave in a medium is affected by <u>d</u><u>e</u><u>n</u><u>s</u><u>i</u><u>t</u><u>y</u>,<u> </u><u>w</u><u>a</u><u>v</u><u>e</u><u>l</u><u>e</u><u>n</u><u>g</u><u>t</u><u>h</u> and <u>t</u><u>e</u><u>m</u><u>p</u><u>e</u><u>r</u><u>a</u><u>t</u><u>u</u><u>r</u><u>e</u><u> </u>:)
(Good luck on your test and mark me brainliest if this helps)
I think it is 100 dB .I holp it is help.