Answer:

Explanation:
A body has acceleration when there is a change in the velocity vector, either in magnitude or direction. In this case we only have a change in magnitude. The average acceleration represents the speed variation that takes place in a given time interval.
a)

b)

<h3>
Answer:</h3>
30.4 km/hr
<h3>
Explanation:</h3>
<u>We are given</u>;
- Speed in the first 2 hours as 25 km/hr
- Speed in the next 3 hours as 34 km/hr
We are required to determine the average velocity in km/hr
- To get the average velocity we divide total distance by total time.
- Thus, we need to determine the total distance
Distance = Speed × time
Distance covered in the first 2 hours;
= 25 km/hr × 2 hours
= 50 km
Distance in the next 3 hours
= 34 km/hr × 3 hours
= 102 km
Therefore, total distance = 50 km + 102 km
= 152 km
Total time = 2 hrs + 3 hrs
= 5 hours
Therefore;
Average speed = 152 km ÷ 5 hours
= 30.4 km/hr
Thus, the average speed is 30.4 km/hr
Answer:
a = 9.94 m/s²
Explanation:
given,
density at center= 1.6 x 10⁴ kg/m³
density at the surface = 2100 Kg/m³
volume mass density as function of distance

r is the radius of the spherical shell
dr is the thickness
volume of shell

mass of shell


now,

integrating both side



we know,




a = 9.94 m/s²
Answer:
A. 
B. 
C. 
D.
Explanation:
Given:
- no. of moles of oxygen in the cylinder,

- initial pressure in the cylinder,

- initial temperature of the gas in the cylinder,

<em>According to the question the final volume becomes twice of the initial volume.</em>
<u>Using ideal gas law:</u>



A.
<u>Work done by the gas during the initial isobaric expansion:</u>




C.
<u>we have the specific heat capacity of oxygen at constant pressure as:</u>

Now we apply Charles Law:



<u>Now change in internal energy:</u>



B.
<u>Now heat added to the system:</u>



D.
Since during final cooling the process is isochoric (i.e. the volume does not changes). So,