Car X traveled 3d distance in t time. Car Y traveled 2d distance in t time. Therefore, the speed of car X, is 3d/t, the speed of car Y, is 2d/t. Since speed is the distance taken in a given time.
In figure-2, they are at the same place, we are asked to find car Y's position when car X is at line-A. We can calculate the time car X needs to travel to there. Let's say that car X reaches line-A in t' time.
Okay, it takes t time for car X to reach line-A. Let's see how far does car Y goes.
We found that car Y travels 2d distance. So, when car X reaches line-A, car Y is just a d distance behind car X.
Answer:
, charges are both positive or both negative
Explanation:
The electrostatic force between the two spheres is given by
where
k is the Coulomb's constant
q1 and q2 are the charges on the two spheres
r is the distance between the centres of the two spheres
In this problem, we have
is the force
is the distance between the spheres
because the two spheres have identical charge
Solving the formula for q, we find
And the two charges have the same sign (so, both positive or both negative), since the sign of the force is positive (+0.30 N), so it is a repulsive force.
Answer:
should be d because friction allows things to go faster or slower
Answer:843.75kg
Explanation:
kinetic energy(ke)=432000j
Velocity(v)=32m/s
Mass(m)=?
Ke=(mxv^2)/2
432000=(mx32^2)/2
432000=(mx32x32)/2
Cross multiplying we get
432000x2=(mx1024)
864000=1024m
Divide both sides by 1024
864000/1024=1024m/1024
843.75=m
m=843.75kg
B. force, distance, and time
Take a look at the definition of a Joule (SI unit of work) and the definition of a Watt (SI unit of power). They're (kg*m^2)/s^2 for work and (kg*m^2)/s^3 for power. Another definition for work is Newton Meter which is force times distance, and since you can define work as force times distance, then power is work per second. So it looks like you need force and distance to calculate work, and then time since power is work over time. So of the 4 choices, we've been given, let's see if any of them allow us to calculate both work and power.
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a. energy, force, and time
* OK. Force will get us Newtons. But how much work do you have, don't know. Since work is force times distance. So can't get work. And without getting work, can't get power. Wrong answer.
b. force, distance, and time
* Force over distance nicely defines work. And time is essential since power is work over time. So this looks to be very good choice.
c. force, mass, and distance
* Have a problem here. Time is pretty essential since all of the SI units for work and power have seconds hiding somewhere in their definition. So this is the wrong answer.
d. mass, force, and energy
* Same issue, no time element here. So wrong answer.
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