Answer:
S = Vo t + 1/2 a t^2 distance traveled
t = (V2 - V1) / a = (0 - 21) / -3.5 = 6 sec time to stop
S = 21 * 6 - 3.5 * 6^2 / 2 = 63 m distance traveled
Answer:
15.67 m/s
Explanation:
The ball has a projectile motion, with a horizontal uniform motion with constant speed and a vertical accelerated motion with constant acceleration g=9.8 m/s^2 downward.
Let's consider the vertical motion only first: the vertical distance covered by the ball, which is S=50 m, is given by

where t is the time of the fall. Substituting S=50 m and re-arranging the equation, we can find t:

Now we now that the ball must cover a distance of 50 meters horizontally during this time, in order to fall inside the carriage; therefore, the velocity of the carriage should be:

First, we need to convert the pressure in SI units. Keeping in mind that

:

The initial and final volume of the gas are (keeping in mind that

):


So, the work done on the gas by the surrounding is

And the final positive sign means that this work corresponds to an increase in internal energy of the gas.
Answer:
A) object moves 20 N [West] or -20 N [East]
B) object moves 6 N [South] or -6 N [North]
C) object moves 90 N [West] or -90 N [East]
D) object does not move and is at rest*
*Rest means 0
Why:
A)both forces from north and south that are pushing against the object neutralize each other. Assume that north is positive and south is negative: 20 [N] + (-20) [S] = 0
On West and east, you can see that west has a greater force. Assume that west is negative and east is positive: 50 [E] + (-70) [W] = -20 [E]
Answer:Principle of rectilinear propagation of light
Explanation:Principle of rectilinear propagation of light
Rectilinear propagation of light refers to the propensity of light to travel along a straight line without any interference in its trajectory. ... It is because light travels along a straight line and leaves only the areas where the object interferes.