Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer : The correct option is (A).
Explanation :
The relation between speed of sound and the density of medium is given by :
where
B is the bulk modulus
and is the density of the medium.
So, it is clear that the speed of sound is inversely proportional to the density of medium i.e.
The correct graph (A). From the graph it is clear that when density of medium approaches to zero, the speed of sound tends to infinite and vice versa.
Answer:
The pitching speed of the ball is 19.7 m/s
Explanation:
- Here, we can use the third equation of motion,
- whereas v represents the final velocity, u represents initial velocity, a is the acceleration due to gravity and s is the displacement or distance an object traveled
- Here, the initial velocity of the the ball is given as zero and the acceleration due to gravity is 9.8 , the distance 's' is given as 20 m
- Using the equation,
- Hence, the pitching speed of the ball is 19.7 m/s
Answer:
Evaluate the following numerical expressions.
6 + 3 • 4 =
18
(6 + 3) ÷ (4 – 5) =
Explanation:
Evaluate the following numerical expressions.
6 + 3 • 4 =
18
(6 + 3) ÷ (4 – 5) =
Answer:
distance
Explanation:
F=GmM/r^2
if r increases in this equation, F would decrease
for example if r = 1 and increase to 2,
when r = 1, F = GmM
when r = 2 F = GmM/4
GmM < GmM/4
so when r increases F decreases