# Answered: Ranking periods of oscillat...

In (e), the motion is damped oscillation. The resistive force would slightly decrease the frequency and thus increase its period. Also your ranking seems reversed to what you were discussing — e.g. in (d), k is increased significantly, so T would decrease and be the smallest among all.

# HW 10 Question 6

So I am having problems solving for the height of Block M2 after the collision. I have gotten the height of block one through the conservation of energy and momentum methods, and tried to re-substitute values and it was incorrect. Help?

# Ranking periods of oscillating motion...

A block with mass m = 0.4 kg oscillates with amplitude A = 0.4 m at the end of a spring with force constant k = 15 N/m on a frictionless, horizontal surface. Rank the periods of the following oscillating systems from greatest to smallest. If any periods are equal, show their equality in your ranking. (Use only “>” or “=&# [...]

# Answered: prelab 10 part 4

If the spring is stretched to provide a force -kx, and if the cart is stationary, the net force on the cart should be zero. The key to the question in Web Assign may be incorrect.

# Answered: What are the final speed an...

In this collision problem, the total momentum would be conserved ||P_i=P_f||.
Assume astronaut 1 is on the left and 2 on the right. So the velocity of the apple is in +x direction and the velocity of the orange is towards -x. The momentum before collision:$$\sum P_{xi}=M_a(1.05)+M_o(-1.19)$$ $$\sum P_{yi}=0$$
After the collision, $$\sum [...]

# prelab 10 part 4

In the lab, we have a cart on a ramp tilted at angle θ and attached to a spring at the top of the ramp. When the spring is stretched, what is the magnitude of the total force on the cart?

# What are the final speed and directio...

Two astronauts on opposite ends of a spaceship are comparing lunches. One has an apple, the other has an orange. They decide to trade. Astronaut 1 tosses the 0.120kg apple toward astronaut 2 with a speed of vi,1 = 1.05m/s . The 0.170kg orange is tossed from astronaut 2 to astronaut 1 with a speed of 1.19m/s . Unfortunately, the fruits collide [...]

# Answered: HW question 3, part B

First, the rear wheel and rear sprocket would have the same angular velocity ||\omega||. Then by finding angular velocity of the rear sprocket, you can get the ||\omega|| of the rear wheel. The rear sprocket and the chain are linked or "bounded" so you will have $$\omega r_{sprocket}=V_{chain}$$
Then in part C, the wheel’s ||\ [...]

# HW question 3, part B

In the question about the bike wheel. In part B why should I divide the chain velocity by the radius of the rear sprocket. What does this actually do, how is the omega of the wheel affected by the rear sprocket?

# Answered: Hw 9 Problem 11

Use ||\sum F=0|| and ||\sum \tau=0||, which gives:$$U-D-F=0$$ and $$DL_3-FL_2=0$$
Here we picked the point B as the rotating axis. Solve for D and U.

# Answered: Problem 4 from HW 9

The net torque can be found as the difference between the torque from the top belt and the bottom belt: $$T_1R-T_2R=\frac 1 2mR^2\alpha$$
Here ||T_1|| is the tension of the top belt.
Check if you have the sign correct.

# Answered: Itotal=2/5M(R)^2+M(l+d2)^2+...

The first two terms give the solid ball’s moment of inertia relative to the rotational axis — the first term is the solid ball’s ||I_{com}|| and the second term is the parallel axis theorem part. The third term is the moment of inertia of the rod.

# Problem 4 from HW 9

I did 1/2 times mass of flywheel times radius squared of flywheel times angular acceleration, then divided by the radius and added the tension from the upper segment but i got the wrong answer. What did i do wrong?

# Itotal=2/5M(R)^2+M(l+d2)^2+13m(L^2). ...

I would like you to elaborate on the intuitive steps that lead to that formula. Right now, to me, it just seems to pop up. If I was doing this question what in there indicates this.

# Answered: Bullet fired through a bloc...

See the related question http://tutor.leiacademy.org/qa/index.php/40/where-does-the-block-land-on-the-floor

# Answered: Where does the block land o...

There are two steps in the problem. First is the "collision" between the bullet and the block. The momentum is conserved in this but mechanical energy is not. Based on the projectile motion of the bullet, you can find it initial velocity, which is the final velocity right after the collision. Then you would be able to use momentum c [...]

# Answered: Quiz on ‘RotationR...

It will have angular acceleration and angular velocity involved. Moment of inertia, torque and angular dynamics will also be included.

# Answered: From this equation U1+Kr1+K...

In general, for any rotational object, you can consider its total kinetic energy as the sum of rotational K around its center of mass and its transnational kinetic energy of the center of mass. Or in certain cases like in this problem when the rotational axis is clearly fixed, you can consider it as having only rotational kinetic energy [...]