Answer:
Final temperature,
Explanation:
Given that,
Mass of silver ring, m = 4 g
Initial temperature,
Heat released, Q = -18 J (as heat is released)
Specific heat capacity of silver,
To find,
Final temperature
Solution,
The expression for the specific heat is given by :
So, the final temperature of silver is 21.85 degrees Celsius.
If we pull an object vertically upwards then we need to apply a force which is equal in the magnitude of the weight of the object
now when we pull the same object upwards along an inclined plane with angle then we require a force which will balance the component of weight along the inclined
so it is given as
so as if we compare the two forces we can say that since the value of sine is always less than 1 for an angle less than 90 degree
so in the 2nd case when we pull the object along the inclined plane it will require less effort
so correct answer is
<em>A. reduce effort</em>
Answer:
619.8 N
Explanation:
The tension in the string provides the centripetal force that keeps the rock in circular motion, so we can write:
where
T is the tension
m is the mass of the rock
v is the speed
r is the radius of the circular path
At the beginning,
T = 50.4 N
v = 21.1 m/s
r = 2.51 m
So we can use the equation to find the mass of the rock:
Later, the radius of the string is decreased to
r' = 1.22 m
While the speed is increased to
v' = 51.6 m/s
Substituting these new data into the equation, we find the tension at which the string breaks: