Answer:
<em>Answer: positive velocity & negative acceleration</em>
Explanation:
<u>Accelerated Motion</u>
Both the velocity and acceleration are vectors because they have magnitude and direction. When the motion is restricted to one dimension, i.e. left-right or up-down, the direction is marked with the sign according to some preset reference.
The locomotive is moving at a certain speed with a (so far) unknown sign but the acceleration has a negative sign. Since the locomotive comes to a complete stop it means the velocity and the acceleration are of opposite signs.
Thus the velocity is positive.
Answer: positive velocity & negative acceleration
Answer:
Question 1)
a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

where α is the angular acceleration.
In order to continue this question, the radius of the drums should be given.
Let us denote the radius of the drums as R, the angular acceleration of drum B is
α = 0.5/R.
b) The distance travelled by the drums can be found by the following kinematics formula:

One revolution is equal to the circumference of the drum. So, total number of revolutions is

Question 2)
a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

b) 
Answer:
The current is halved
Explanation:
The relationship between the current and the resistance is given by Ohm's Law, as follows:

where,
V = Voltage
I = Current
R = Resistance
Therefore, if we double the resistance:

Hence the correct option is:
<u>The current is halved</u>
Answer:
wut goes up must come down i dunno lol
Explanation:
Answer:
They have same density
Explanation:
The density of an object is defined as

where
m is the mass of the object
V is its volume
Let's call
and
the mass and the volume of ball C, respectively. Therefore, the density of ball C is:

We know that the volume of ball C is 3 times the volume of ball D, so

And we also know that ball D has 1/3 the mass of ball C:

So, the density of ball D is:

Therefore, the two balls have same density.