Answer:
v = 72 km / h
Explanation:
The definition of average speed is the distance traveled between the time interval
v = Δx / Δt
let's find the distance traveled
x = 60 + 30
x = 90 km
time spent, all time must be included, travel time and when stopped
t = 0.45 + 0.15 + 0.5+ 0.15
t = 1.25 h
we substitute in the initial equation
v = 90 / 1.25
v = 72 km / h
in going from one city to the other
Answer:
a) 230 Km b) 76.7 km/h c) Please see below
Explanation:
a) If we can neglect the time while the driver accelerated, the movement can be divided in two parts, each of them at a constant speed:
⇒ 
b) The average x component of velocity, can be calculated applying the definition of average velocity, as follows:
If we choose t₀ = 0 and x₀ = 0, replacing xf and t by the values we have already found, we can find vavg,x as follows:
c) The found value of avg,x is not the same as the arithmetic average of the initial and final values of vx (70 Km/h) due to the time traveled at both velocities was not the same.
If the driver had droven half of the time (1.5 h) at 50 km/h and the other half at 90 km/h, total displacement would have been as follows:
Applying the definition of average velocity once more:
which is the same as the arithmetic average of the initial and final values of vₓ.
The airplane's speed relative to the ground is
√ (100² + 25²)
= √ (10,000 + 625)
= √ 10,625
= 103.08 km/hr .
The angle of its velocity north of west is
the angle whose tangent is (25/100)
arctan(25/100) = 14° north of west .
(bearing = 284°)
Answer:
<h2>e. 7.1 MN approx.</h2>
Explanation:
Step one:
given data
density of water= 1000kg/m^3
the dimension of the barge
width= 10m
length= 60m
depth of the boat in the water= 1.2m
Hence the volume occupied by the boat is
volume=10*60*1.2
volume= 720m^2
Step two:
Required is the weight of the barge
we can first find the mass using the relation
density = mass/volume
mass= density*volume
mass= 1000*720
mass= 720000kg
Step three:
Weight =mg
g=9.81m/s^2
W=720000*9.81
W=7063200N
divided by 10^6
W=7.06MN
W=7.1MN approx.
Answer:
Number of times a cricket chirps.
Explanation:
Let us use a graph to understand the function Here the entomologist wants to know the effect of temperature on the number of chirps of a cricket so, the chirps should vary with temperature. The opposite cannot be true i.e., the temperature is not dependent on the number of chirps rather the number of chirps are dependent on temperature.
So, the x axis will be represent the temperature and the y axis will represent the number of chirps.
Hence, the dependent variable will be number of times a cricket chirps i.e., the y axis.
