3. If you roll a ball up a hill, it undergoes positiveacceleration. True or false
1 answer:
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1) -0.5 m/s
We can solve the first part of the problem by using the law of conservation of momentum. In fact, the total momentum of the cannon - shell system must be conserved.
Before the shot, both the cannon and the shell are at rest, so the total momentum is zero:
After the shot, the momentum is:
where
M = 2000 kg is the mass of the cannon
m = 10 kg is the mass of the shell
v = 100 m/s is the velocity of the shell (we take as positive the direction of motion of the shell)
V = ? is the velocity of the cannon
Since momentum is conserved, we can write
And solving for V, we find the velocity of the cannon:
where the negative sign indicates that the cannon moves in the direction opposite to the shell.
2) 0.5 m
The motion of the cannon is a uniformly accelerated motion, so we can solve this part by using suvat equation:
where
v is the final velocity of the cannon
u = 0.5 m/s is the initial velocity of the cannon (now we take as positive the initial direction of motion of the cannon)
is the deceleration of the cannon
s is the distance travelled by the cannon
The cannon will stop when v = 0; substituting and solving the equation for s, we find the minimum safe distance required to stop the cannon:
Answer:
C) The rate of change from potential to kinetic energy is exponential.
Explanation:
As we know that total mechanical energy must be conserved here
As we know that there is no friction force on this system of electromagnet and nail
So here we can say that that
Magnetic potential energy of the nail + electromagnet system will convert into kinetic energy of the nail as it is released.
So we will have
Initial potential energy = work done to move it away by 10 cm
now as the nail is released then this potential energy will start to convert into kinetic energy
So here correct answer must be
C) The rate of change from potential to kinetic energy is exponential.