Answer:
That when you leave the ice setting without foil, it melts slower. When you put the piece of ice in the foil it melts faster than just letting it set without foil. I really hope this helps.
Explanation:
Answers:
a)The balloon is 68 m away of the radar station
b) The direction of the balloon is towards the radar station
Explanation:
We can solve this problem with the Doppler shift equation:
(1)
Where:
is the actual frequency of the sound wave
is the "observed" frequency
is the velocity of sound
is the velocity of the observer, which is stationary
is the velocity of the source, which is the balloon
Isolating :
(2)
(3)
(4) This is the velocity of the balloon, note the negative sign indicates the direction of motion of the balloon: It is moving towards the radar station.
Now that we have the velocity of the balloon (hence its speed, the positive value) and the time () given as data, we can find the distance:
(5)
(6)
Finally:
(8) This is the distance of the balloon from the radar station
Cells are grouped together to carry out specific functions. A group of cells that work together form a tissue. Your body has four main types of tissues, as do the bodies of other animals. These tissues make up all structures and contents of your body.
Answer:
Explanation:
The center of mass of the system (two girls) is constant, as the velocity of the center of mass of the system is also constant.
<u>The initial velocity of the system is zero, since both girls are at rest.</u> So the velocity of the total system at any point should be zero as well.
This is true, because there is no friction between the girls and the ground. Otherwise, the velocity of the center of mass wouldn't be constant.
Answer:
a) a = 19.0 m/s²
b) a = 2.9 m/s²
Explanation:
a) We draw the free body diagram of the box. There are 4 forces: the normal force N, the weight mg, the constant force F and the kinetic frictional force μ_kN. We can take the coordinate system which is rotated 55° from the horizontal, to ease the calculations. So, we write the equations of motion in each axis:
Substituting the expression for N in the first equation, we have:
If we plug in the given values, we have:
Since we chose the right-downward direction as positive, the positive sign in this case means that the box is accelerated downwards above the ramp.
b) In this case, the constant force F and the kinetic frictional force μ_kN point to the opposite side. In other words, we can just only change the sign of this two forces in the equations of part (a) and obtain:
Plugging in the given values:
Since we chose the right-downward direction as positive, the negative sign in this case means that the box is accelerated upwards above the ramp.
This means that the magnitude of the acceleration in this case is 2.9m/s².