(a) This is a freefall problem in disguise - when the ball returns to its original position, it will be going at the same speed but in the opposite direction. So the ball's final velocity is the negative of its initial velocity.
Recall that
We have 
, so that
(b) The speed of the ball at the start and at the end of the roll are the same 8 m/s, so the average speed is also 8 m/s.
(c) The ball's average velocity is 0. Average velocity is given by 
, and we know that .
(d) The position of the ball 
at time 
is given by
Take the starting position to be the origin, 
. Then after 6 seconds,
so the ball is 42 m away from where it started.
We're not asked to say in which direction it's moving at this point, but just out of curiosity we can determine that too:
Since the velocity is positive, the ball is still moving up the incline.
Answer: q = 2.781e-9C = 2.781nC
E=200C
Explanation:
E = Qd/(2πEor^3)
Where
E=Electric field intensity
Q=Charge
d=distance between the dipole=0.008m
Eo=permitivitty
400 N/C = Q(0.80e-2 m)/(2πε*(10e-2 m)^3)
Q= (400* 2* 3.142 * 8.85 x 10-12 * 0.1^3)/0.008
q = 2.781e-9C = 2.781nC
b)
Though the dipole are two separate charges. And since the point is on the x-axis, the electric field strengths are equivalent. The magnitude of the vector sum is:
E = kq*2sin θ/r^2
= 2(8.99e9 N*m^2/C^2)(2.781e-9 C)*sin(arctan(.4/10))/(10e-2 m)^2
= 2(8.99e9) * (2.781e-9) * sin(2.290)/(10e-2 m)^2
=200 C
The distance covered by Arthur is
3t
The distance covered by Betty from where Arthur started is
100 - 2t
They meet each other when this distance is equal
3t = 100 - 2t
t = 20 s
Since the dog has a constant speed of 5m/s, the distance that Spot has run is
5 m/s (20s) = 100 m
Answer:
The equipment to use is: a beaker, a fixed amount of water, a thermometer.
The mass of water, the time, the temperature for each time should be noted and a graph of Temperature versus time should be made
Explanation:
The design of an experiment is to place the beaker in the microwave, with a good amount of water (approximately ⅔ of its capacity) and turn it on for small periods of time, generally the minimum is 30 s, quickly open the microwave, place a thermometer or better yet an infrared thermometer to measure the temperature of the water; repeat this several times.
The advantage of the infrared thermometer is that it reduces the transfer of heat between the water and the thermometer.
The mass of water, the time, the temperature for each time should be noted and a graph of Temperature versus time should be made.
The equipment to use is: a beaker, a fixed amount of water, a thermometer.
The main precaution that must be taken is not to open the microwave while it is on.
Answer:
57.1 km/hr
Explanation:
To find the average speed you take the total distance divided by the total elapsed time.
So, the total distance is 140 + 60 = 200
the total elapsed time is found by taking 140/70=2 and 60/40=1.5
2+1.5=3.5
The plug the numbers into the equation,
200/3.5=57.1
