Answer:
B. t = 0.250s
Explanation:
A. An image with the sketch of the bat emitting a sound, which reflects on a surface and return to the bat is attached below.
B. In order to calculate the time that the pulse emitted by the bat, return to the bat, you first calculate the time that pulse takes to arrive to the object.
You use the following formula:
(1)
x: distance to the object = 43m
t: time = ?
v: speed of sound beat = 343 m/s
You solve the equation (1) for t:
The time on which the bat hears the echo is twice the value of t, that is:
The time on which bat heart the echo of its sound, from the moment on which bat emitted it, is 0.250s
Answer : The correct option is, (d) 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of copper = 
= specific heat of water = 
= mass of copper = 120 g
= mass of water = 300 g
= final temperature of mixture = 
= initial temperature of copper = ?
= initial temperature of water = 
Now put all the given values in the above formula, we get:
Therefore, the temperature of the kiln was,
Answer:
B. The elasticity of demand is -0.126
Explanation:
% Change in Quality demand = -2.65% (negative because of drop)
% Change in price = 21%
Elasticity of demand is given by
The Elasticity of demand is -0.12619
The amount of energy is ALWAYS conserved based on the law of conservation of energy. Therefore, the amount of energy will remain the same.
Since weight is the force an object is exerting on another object, and the formula to calculate force is Force = Mass * Acceleration, the answer to your question is 196 N, since the mass of the cannonball times Earth's gravitational pull equals 196 N.
