(a) As the car is moving with constant velocity, it means the rate change of velocity does not change, therefore the average acceleration of the car is zero.
Thus, there is no acceleration, when velocity is constant.
(b) Average acceleration,
Here, v is final velocity and u is the initial velocity and 
is the time interval.
As twelve seconds later, the car is halfway around the track and traveling in the opposite direction with the same speed, therefore
Thus, the average acceleration of the car is 
in the direction to the left.
Answer:
Pe is stored energy to do work Pe is stored in objects that are at rest
KE defined as the energy of motion
began to move
Not sure about the rest
hope this helps
Explanation:
Answer: E = 0.85
Therefore the efficiency is: E = 0.85 or 85%
Explanation:
The efficiency (e) of a Carnot engine is defined as the ratio of the work (W) done by the engine to the input heat QH
E = W/QH.
W=QH – QC,
Where Qc is the output heat.
That is,
E=1 - Qc/QH
E =1 - Tc/TH
where Tc for a temperature of the cold reservoir and TH for a temperature of the hot reservoir.
Note: The unit of temperature must be in Kelvin.
Tc = 300K
TH = 2000K
Substituting the values of E, we have;
E = 1 - 300K/2000K
E = 1 - 0.15
E = 0.85
Therefore the efficiency is: E = 0.85 or 85%
Answer:
0 1 2 3 4 . because the particle moved with a constant acceleration
Answer:
A laser is created when the electrons in atoms in special glasses, crystals, or gases absorb energy from an electrical current or another laser and become “excited.” The excited electrons move from a lower-energy orbit to a higher-energy orbit around the atom's nucleus.
