Answer:
Density of unknown liquid is 
Explanation:
When rock is suspended in air then the weight of the rock is counter balanced by the tension force in the string
So here we have

now when the rock is immersed in water then the tension in the string is and buoyancy force due to water is counter balanced by the weight of the object
so here we have



now we have


now when the rock is immersed into other liquid then we have



now we have


Answer: The tension in the string is zero
Explanation:
Answer:
0.83 m/s
Explanation:
FIrst of all, we have to find the time of flight, i.e. the time the baseball needs to reach the ground. This can be done by using the equation for the vertical motion:

where
h is the initial height
u = 0 is the initial vertical velocity
g = 9.8 m/s^2 is the acceleration of gravity
t is the time
Substituting h = 1.8 m and solving for t,

We know that the horizontal distance travelled by the ball is
d = 0.5 m
Therefore, we can find the horizontal velocity (which is constant during the whole motion):

Answer:
14cm
Explanation:
Mass per gram of the piece of wire;
2g of the wire is found in 1m
Since
100cm = 1m;
So;
100cm of the wire contains 2g of the wire
To provide 0.28g
Since;
2g of wire is made up of 100cm
0.28g of wire will be contained in
= 14cm
14cm of the wire will contain 0.28g