Answer: c. they will hit the ground at the same time
Explanation:
The volume of both objects is almost the same, so the force of friction will be the same in each one, so we can discard it.
Now, when yo drop an object, the acceleration of the object is always g = 9.8m/s^2 downwards, independent of the mass of the object.
So if you drop two objects with the same volume but different mass, because the acceleration is the same for both of them, they will hit the ground at the same time, this means that the density of the object has no impact in how much time the object needs to reach the floor.
So the correct option is c
Answer:

Explanation:
First of all, we need to calculate the total energy supplied to the calorimeter.
We know that:
V = 3.6 V is the voltage applied
I = 2.6 A is the current
So, the power delivered is

Then, this power is delivered for a time of
t = 350 s
Therefore, the energy supplied is

Finally, the change in temperature of an object is related to the energy supplied by

where in this problem:
E = 3276 J is the energy supplied
C is the heat capacity of the object
is the change in temperature
Solving for C, we find:

Answer:
Explanation:
There will be loss of potential energy due to loss of height and gain of kinetic energy .
loss of height = R - R cos 14 , R is radius of hemisphere .
R ( 1 - cos 12 )
= 13 ( 1 - .978 )
h = .286 m
loss of potential energy
= mgh
= m x 9.8 x .286
= 2.8 m
gain of kinetic energy
1/2 m v ² = mgh
v² = 2 g h
v² = 2 x 9.8 x 2.8
v = 7.40 m /s