Answer:1 because
Explanation: it’s pointing to the earth and gravity
Pulls things down to earth
Power is the amount of work done over a period of time. If you will put that into an equation, the formula of power will be:
P = W/t
Where:
P = power
W=work
t = time
Your problem already provides you with work and time so all you need to do is divide:
P = W/t
P = 50J/30s
P = 1.67 W
Answer:
a) 42 m/s, positive direction (to the east), b) 42 m/s, negative direction (to the west).
Explanation:
a) Let consider that Car A is moving at positive direction. Then, the relative velocity of Car A as seen by the driver of Car B is:

42 m/s, positive direction (to the east).
b) The relative velocity of Car B as seen by the drive of Car A is:

42 m/s, negative direction (to the west).
it is true. the trajectory reaches the value of zero at the top
For this case you must first know the definition of density.
D = m / v
where,
m: mass
v: volume.
You can then write the following hypothesis:
IF you know two physical characteristics of an object then you can determine the density. First weigh the object, THEN measure its volume BECAUSE the density is the quotient between the mass and the volume of an object.