The acceleration due to gravity is lower on the Moon than on Earth. Which one of the following statements is true about the mass
1 answer:
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Answer
Acceleration=>10.20mm/s
Explanation
Below in image
Answer:
(a) v-bullet = 399.04 m/s
(b) I = 2.38 kg m/s
(c) T = 2.59 N
Explanation:
(a) To calculate the initial speed of the bullet, you first take into account that the kinetic energy of both wood block and bullet, just after the bullet impacts the block, is equal to the potential gravitational energy of block and bullet when the cord is at 60° respect to the vertical.
The potential energy is given by:
(1)
U: potential energy
M: mass of the wood block = 1 kg
m: mass of the bullet = 6g = 6.0*10^-3 kg
g: gravitational constant = 9.8m/s^2
h: distance to the ground
The distance to the ground is calculate d by using the information about the length of the cord and the degrees of the cord respect to the vertical:
The potential energy is:
Next, the potential energy is equal to kinetic energy of the block and the bullet at the beginning of its motion:
Next, you use the momentum conservation law, in order to calculate the speed of the bullet before the impact:
(2)
v1: initial velocity of the wood block = 0m/s
v2: initial speed of the bullet
v: speed of bullet and block = 2.38m/s
You solve the equation (2) for v2:
The speed of the bullet before the impact with the wood block is 399.04 m/s
(b) The impulse is gibe by the change in the velocity of the block, multiplied by the mass of the block:
The impulse is 2.38 kgm/s
(c) The force on the cord after the impact is equal to the centripetal force over the block and bullet. That is:
The force on the cord after the impact is 2.59N
Answer:
For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:
d) More information is needed
(The relation between the masses is not given)
Explanation:
For this case we know the following info:
Where c means specific heat for the substance A and B.
We also know that the initial temperatures for both sustances are equal:
We assume that we don't have melting or vaporization in the 2 substances. So we just have presence of sensible heat given by this formula:
And for this case we know that Both A and B are at the same initial temperature when equal amounts of energy are added to them, so then we have this:
And if we replace the formula for sensible heat we got:
And if we replace for the change of the temperature we got:
And since we have this:
For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:
d) More information is needed
(The relation between the masses is not given)