Answer:
464.69 m
Explanation:
First car
Second car
Distance = Speed × Time
Here, the time taken and the distance traveled will be the same
Equating the two equations
So, the first would have to move 
in order to overtake the second car.
Let car A's starting position be the origin, so that its position at time <em>t</em> is
A: <em>x</em> = (40 m/s) <em>t</em>
and car B has position at time <em>t</em> of
B: <em>x</em> = 100 m - (60 m/s) <em>t</em>
<em />
They meet when their positions are equal:
(40 m/s) <em>t</em> = 100 m - (60 m/s) <em>t</em>
(100 m/s) <em>t</em> = 100 m
<em>t</em> = (100 m) / (100 m/s) = 1 s
so the cars meet 1 second after they start moving.
They are 100 m apart when the difference in their positions is equal to 100 m:
(40 m/s) <em>t</em> - (100 m - (60 m/s) <em>t</em>) = 100 m
(subtract car B's position from car A's position because we take car A's direction to be positive)
(100 m/s) <em>t</em> = 200 m
<em>t</em> = (200 m) / (100 m/s) = 2 s
so the cars are 100 m apart after 2 seconds.
Answer:
The energy that the truck lose to air resistance per hour is 87.47MJ
Explanation:
To solve this exercise it is necessary to compile the concepts of kinetic energy because of the drag force given in aerodynamic bodies. According to the theory we know that the drag force is defined by
Our values are:
Replacing,
We need calculate now the energy lost through a time T, then,
But we know that d is equal to
Where
v is the velocity and t the time. However the time is given in seconds but for this problem we need the time in hours, so,
(per hour)
Therefore the energy that the truck lose to air resistance per hour is 87.47MJ
Answer:
OK draw a diagram - you have the force from (b) acting sown the slope and a component of the weight. Use F=ma to get the deceleration and then use SUVAT. Post your working if this doesn't work.
friction = 900N
braking = 3100N
total = 4000N
w= mxg = 1000*9.81= 9810N
total = 9810 + 4000 = 13810N
force/mass = 13810/1000 = 13.81ms^-2
then using v^2 = u^2 + 2as, i get s as 14 but it is incorrect
Explanation:
