First speed = 20km/h
Time = 3 hours
Distance = 3×20
<h3> = <u>60 km</u></h3>
Second speed = 30km/h
Time = 4 hours
Distance = 4×30
<h3> = <u>120 km</u></h3>
Total distance = 60+120 = <u>180km</u>
Total time = 3+4 =<u> 7 hours</u>
Average speed = 180/7
<h3> = <u>25.71</u><u> </u><u>km</u><u>/</u><u>h</u></h3>
Hope this will help...
Kinetic Energy = 1/2 * m * v²
1/2 * 30 * 20²
1/2 * 30 * 400
12000/2
6000 J.
Answer:
v = 4.18 m/s
Explanation:
given,
frequency of the alarm = 872.10 Hz
after passing car frequency she hear = 851.10 Hz
Speed of sound = 343 m/s
speed of the jogger = ?
speed of the


v_o = 872.1 - 10.5

The speed of jogger


v = 4.18 m/s
Answer:
The answer to your question is 5.4 cm
Explanation:
This problem refers to calculate the change in length in one dimension due to a change in temperature.
Data
α = 12 x 10⁻⁶
Lo = 150 meters
ΔT = 30 °C
Formula
ΔL/Lo = αΔT
solve for ΔL
ΔL = αLoΔT
Substitution
ΔL = (12 x 10⁻⁶)(150)(30)
Simplification
ΔL = 0054 m = 5.4 cm