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...
Answer:
3136 Joules
Explanation:
Applying,
P.E = mgh.............. Equation 1
Where P.E = potential energy, m = mass of the cinder block, h = height of the platform, g = acceleration due to gravity.
From the question,
Given: m = 16 kg, h = 20 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
P.E = 16(20)(9.8)
P.E = 3136 Joules
Hence the potential energy of the cinder block is 3136 Joules
Answer:
115, 80, 15m
Explanation
t1 = 14s
t2 = 18s
change in time = 4s (18-14)
r(final) = r(initial) + (average velocity) x (change in time)
multiply the average velocity with the change in time
= (4, 0, -3) x 4 = 16, 0, -12
now we'll add this value to the initial position of the car
(99, 80, 27)m + (16, 0, -12)m = (115, 80, 15)m
Answer:
Explanation:
From A to B
distance traveled with velocity 
in time 
from B to C
distance traveled is 0.5 d with 
and 
velocity for half-half time
divide 1 and 2 we get
Now average velocity is given by
taking common
The point of contact the path difference is zero but one of the interfering ray is reflected so the effective path difference becomes λ/2 thus the condition of minimum intensity is created in the center.
