Answer:
- 0.25m/s²
Explanation:
Given parameters:
Initial velocity = 40m/s
Final velocity = 30m/s
Time taken = 40s
Unknown:
Acceleration of the car = ?
Solution:
Acceleration is the rate of change of velocity with time.
So;
Acceleration =
Acceleration =
= - 0.25m/s²
This implies that the car will decelerate at a rate of 0.25m/s²
Answer:
The work done by the frictional force is 600J.
Explanation:
The work
done by the frictional force is
.
Now,
and
; therefore,


Hence, the work done by friction is 660J.
It's the rate that energy is used or supplied
Answer: 
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed= 16.7 kJ = 16700 J (1kJ=1000J)
m= mass of benzene = 225 g
c = specific heat capacity = 1.74 J/gK
Initial temperature of the water =
= 20.0°C = 293 k 
Final temperature of the water =
= ?
Change in temperature ,
Putting in the values, we get:


The final temperature will be 