Answer:
t = 75.4 s
v = 26.9 m/s
Explanation:
Part1 :
v1 = 0 m/s
v2 = 32 m/s
a = 2 m/s2
The time needed to reach the final speed is:
v2 = v1 + a*t
32 = 0 + 2*t
t = 16 s
Part 2:
constant speed of 32 m/s for 53 s
Part 3:
v2 = 32 m/s
v3 = 0 m/s
t = 5 s
The acceleration is negative because the car is stopping:
v3 = v2 + a*t
0 = 32 + a*5
a = - 6.4 m/s
a) The total time the car is in motion is:
total time = 16 + 53 + 6.4 = 75.4 s
b) For the average speed you can calculate the total distance and divide it by the total time for an easier way
Part 1
d = (32+0)/2 * 16 = 256 m
Part 2
d = 32 * 53 = 1696 m
Part 3
d = (32+0)/2 * 5 = 80 m
Average speed:
v = (256 + 1696 + 80)/75.4 = 26.9 m/s
Answer:
A) Walking would burn up more energy
B) Walking: 1,914,000 J
Running: 1,386,000 J
C) Even though running is more intense and burns energy at higher rate, it burns energy for a much shorter time than walking.
Explanation:
Watt is a unit for power that is equivalent to Joules per second (J/s). Therefore, to figure out the energy burnt up during an activity, first we need to know how long (in seconds) that activity took.
1- Running
V = 10.0 km/h
d = 5.50 km
t = 5.50/10 = 0.55 h = 0.55(h) *60 (min/h) *60(s/min) = 1,980 s
2- Walking
V = 3.0 km/h
d = 5.50 km
t = 5.50/ = 1.83333 h = 1.83333(h) *60 (min/h) *60(s/min) = 6,600 s
A) Walking would burn up more energy
B) Walking: 1,914,000 J
Running: 1,386,000 J
C) Even though running is more intense and burns energy at higher rate, it burns energy for a much shorter time than walking.
Answer:
0.63m
Explanation:
Volume expansivity = change in volume/original volume×temp change
Volume expansivity p = 3x
p = ∆V/V∆t
x is the linear expansivity
Given
x = 6 x 10^-4
p = 3x
p = 3(6 x 10^-5)
p = 18×10^-5
Volume = 100m³
∆t = 45-10 = 35°C
Required
Change in volume ∆V
Substitute the given values into the formula
18×10^-5 = ∆V/100(35)
18×10^-5 =∆V/3500
∆V = 3500×0.00018
∆V = 0.63m
Hence the increase in volume of the Mercury is 0.63n
Answer:
8.5
Explanation:
to find efficiency take the ratio between the output and input
85/100=output/input
The answer is C -
because reversibility means when taking a break it'll be hard to get back on schedule