Answer:
Option A
The drag force goes up by a factor of 4
Explanation:
Fact:
Drag force is directly proportional to the square of the velocity of a moving object
Therefore, when drag force pushes opposite to the motion as one rides a bicycle, the magnitude of drag force increases by a factor of 4
Answer:
ice
Explanation:
If the toy car is on a smooth surface, there is less friction. Therefore, the car will most likely go faster. Ice has the least friction so the toy car would travel fast.
Scientists review the work of other scientists to validate the results and check the evidence's reliability. The correct option among all the options that are given in the question is the fourth option or the last option or option "D". I hope that this is the answer that has come to your desired help.
Answer:
4m/s
Explanation:
The motion is in downward direction, and the boat is moving with constant velocity, the position of the boat horizontally is 12m before the key fall.
The height difference "h"= ( y- y°)= 45 m
We can determine the needed time the key requires to reach the water using the expression from Newton's law
h= v(o) + 1/2 at^2
g= acceleration due to gravity= 9.8m/s^2
h= v(o) + 1/2 gt^2 -------------------------eqn*)
V(o)= 0 for the key= initial velocity
h= height that the key falls= 45m
If we substitute the above values into eqn(*) we have
We can make t^2 subject of the formula since v(0)= 0
t^2= h/(1/2 g)
= 45/(1/2× 9.8)
t^2= 45/4.9=9.18
t= √9.18
t=3.03 secs
Since the boat was moving with constant velocity,
Then Velocity= distance/ time
= 12/3.03
Velocity= 4m/s
Hence, the speed of the boat is 4m/s
