Answer:
Negative
Explanation:
Observe that the object below moves in the positive direction with a changing velocity. An object which moves in the positive direction has a positive velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a negative acceleration).
Answer:
Electric force, 
Explanation:
Given that,
Electric charge 1, 
Electric charge 2, 
Distance, 
To find,
The electric force between these two sets of charges.
Solution,
There exists a force between two electric charges and this force is called electrostatic force. It is equal to the product of electric charged divided by square of distance between them.

k is the electrostatic constant


So, the electric force between these two sets of charges is
.
Answer : The volume of a sample of 4.00 mol of copper is 
Explanation :
First we have to calculate the mass of copper.


Now we have to calculate the volume of copper.
Formula used :

Now put all the given values in this formula, we get:


Conversion used :

Therefore, the volume of a sample of 4.00 mol of copper is 
Answer:
y = 10.44cos(2t - 0.291) cm
Explanation:
y = Acos(2πt/T + φ) = Acos(2πt/π + φ) = Acos(2t + φ)
v = y' = -2Αsin(2t + φ)
10 = Acos(2(0) + φ) = Acosφ
6 = -2Αsin(2(0) + φ) = -2Asinφ
6/10 = -2Asinφ/Acosφ = -2tanφ
tanφ = -0.3
φ = -0.291 radians
10 = Acos(-0.291)
A = 10/cos(-0.291) = 10.44