Kimmy

The standard free energy of activation of a reaction A is 73.5 kJ mol–1 (17.6 kcal mol–1) at 298 K. Reaction B is one million times faster than reaction A at the same temperature. The products of each reaction are 10.0 kJ mol–1 (2.39 kcal mol–1) more stable than the reactants. (a) What is the standard free energy of activation of reaction B?

What is the standard free energy of activation of reaction B?

A uniform wooden board has a length of 2.3 meters. It's supported to support support 1 and 2. Support 2 exerts a normal force of 38.8 Newtons on the board, and support 1 exerts a normal force of 34.7 Newtons and is located a distance of 0.38 meters from the left end of the board. How far is support 2 from the right end of the board, in centimeters?

A circular object with a moment of inertia of I = c M R2, where c = 0.64 which has mass of 6.2 kg and radius of 0.75 meters, is spinning in place about its center due to the three forces, only, (no weight or normal force is acting on the object). If F1 = 26.3 N, F2 is unknown, and F3 = 24.3 N . If the object started from rest and after 5.2 seconds it is spinning counter-clockwise at 33.1 rad/s, what is the amount of F2 in Newtons?

A circular object with a moment of inertia of I = c M R2, where c is unknown is rolling about its center without slipping down an incline (kinetic friction can be ignored). If it starts from rest at the top of the incline, the length of the incline is 42.7 meters, and its angle of inclination is 28 degrees, and it takes 5.6 seconds to roll down the incline, what is the value of c?

A large tank of water with a density of 1000 kg/m3 is not open to the atmosphere. Instead, it is sealed to a vacuum where the pressure is zero Pascals. A small hole is punched at some distance below the water level. The hole is exposed to a pressure of 3.1 atmospheres of pressure. How far below the water level does the hole need to be punched such that the water just begins to flow out? Answer in meters.

Suppose one brings a spherically shaped helium with a density of .164 kg/m3 to an alien planet. This balloon is inflated to a volume of 28.4 m3 and then a string is attached to it which is attached to a mass of 3.3 kg which is resting on a horizontal surface on the planet. At this volume, the balloon just starts to lift the mass off the surface. What is the density of the atmosphere (the "air") on this planet in g/m3?

NASA, when it sends probes to other planets, uses what is known as a gravitational slingshot. This is when a probe uses the gravitational potential energy a planet to gain kinetic energy. Even though the probe and the planet are not physically colliding, one can treat this problem as a perfectly elastic head on collision between the probe and the planet. Suppose the probe, with a mass of one millionth the mass of the planet, is approaching the planet initially at 269.8 m/s in the negative x direction and the planet is moving at 31.4 m/s in the positive x direction. What is the magnitude of the final velocity of the probe, in m/s, after the collision? Thank you SO much!!

Mass 1 with a unknown mass starts at rest at the top of a frictionless from a height of 13 meters. It then slides down the incline and moves over a horizontal frictionless surface and collides inelastically (head on) with mass 2 which is 25.4 kg and initially at rest. After the collision, the total kinetic energy of both masses is 64% of the initial total kinetic energy of both masses before the collision. What is the amount of mass 1 in kg?

An object with a mass of 23.4 kg is hung from two identical springs vertically. The springs both stretch 0.12 meters from equilibrium with the attached mass. One of the those springs is placed on a horizontal surface without friction and the mass of 23.4 kg is held still next to the spring after it has been compressed 2.03 meters from equilibrium. The 23.4 kg mass is then released and it collides perfectly elastically (head on) on the horizontal surface with a 2.2 kg mass on the horizontal surface which is initially at rest. After the collision, the 2.2 kg mass travels up a frictionless incline which is inclined at 22 degrees. How far up the incline does the mass travel up the incline, in meters, before it stops?

A mass of 9.9 kg is moving in the positive x direction at 6.2 m/s and collides in a perfectly elastic, head on collision with a mass of 12.8 kg moving at 16.7 m/s in the negative x direction. If the collision takes place in a time of 0.21 seconds, what is the magnitude of the average force on the 9.9 kg mass in Newtons?

A Bluray disk is orginally at rest. A mass of 0.28 kg is attached to the Bluray a distance of 0.1 meters from center of the Bluray. The tangential acceleration of the mass is 2.5 m/s2 and is constant. If the Bluray, is spun from rest about its center, how many revolutions does the disk make in order for the mass on the disk have a kinetic energy of 7 Joules?

I did a Physics lab on specific heat capacities of metals and I was just wondering why the measured specific heats I got in my experiment are always lower than the accepted values! Thanks a lot!!

The mass is 22.96 g. Initial temperature is 103 degrees Celsius. Water of mass is 100 g at temperature 23 degrees Celsius. And the final temperature is 26.50 degrees Celsius. Please help me find the specific heat capacity! Thanks a lot!!

Choose the false statement.

A) The hamstrings cross the hip and knee joints.

B) The medial hamstrings promote medial knee (leg) rotation.

C) The hamstrings are prime movers of hip (thigh) flexion and knee (leg) flexion

D) The hamstrings are fleshy muscles of the posterior thigh.

Suppose in 1000 years we colonize in extra solar (outside of our solar system) planet. The planet's mass is 2.3 times larger than Earth's mass and it's radius is 6.4 times larger than the Earth's radius. By share coincidence, the geosynchronous orbit is this planet is the same altitude of that of Earth's geosynchronous orbit. What is the length of a day on this planet in terms of Earth days (24 hours)? The Earth's mass is 5.97 x 1024 kg and its radius 6371 km.

A car is travelling at the bottom of a circular banked road without friction (from the aerial view, the car is on the inside radius). At the bottom of the road, the car's speed is 18 m/s and road is banked at 64.8 degrees. If the car wants to move 10.1 meters up the road (think of it as moving 10.1 meters up an incline), how fast does the car need to travel in m/s, to accomplish this?

A yo-yo with a mass of 1.7 kg with a length of rope of 0.62 meters is spun in a vertical circle, but its speed is not constant as it is affected by gravity. If the yo-yo does a quarter circle from the bottom and the tension in the rope at this point is 57.2 Newton's, how fast was the yo-yo moving at the bottom of the circle in m/s? Hint: use centripetal force to find the tension at the point of the quarter circle in general and then use that to find the final speed at this point. Then just use conservation of energy to find the speed at the bottom.

A roller coaster cart with a mass of 8.4 kg is originally at rest and then it is accelerated by a horizontal force of 21 Newton's applied over a distance of 4 meters over a horizontal, frictionless surface. It then travels down a ramp which has a coefficient of kinetic friction of 0.3 and is inclined at an angle of 64 degrees. It then travels along a horizontal, frictionless surface, and around a circular of radius 10.8 meters. What is the length of the ramp, such that the cart just barely makes it around the loop? Answer in meters.

A mass of 14 kg is moving at a speed of 39 m/s at the bottom of incline which is inclined at an angle of 51.6 degrees. The incline has friction and the coefficient of kinetic friction is 0.6. The mass travels up the incline and stops due to both gravity and friction and then slides back down the incline. When the object slides back down the incline, how fast is it moving at the bottom in m/s?