A chemist finds that when platinum is added to a reaction, the reaction speeds up. He thinks the platinum may be acting as a catalyst. What measurement should the chemist make to determine whether it is a catalyst?

A mouse is walking at 2.45 m/s. He sees a cat and accelerates at 4.92 m/s/s. How much time does it take him to reach a speed of 4.32 m/s?

A train rolls to a stop along a horizontal track without the conductor applying the brakes. What answer choice BEST explains why this occurred? A) The train ran out of momentum. B) The opposing force of friction stopped the train.

A motor with a power of 7.0 * 104 watts lifts a loaded elevator to a height of 20.00 meters for 40 seconds. What is the force exerted by the motor on the elevator?

What does variable mean in science?

It is extremely difficult to play, record, and hear live music in a park or other open space. explain why this is so. Use the word reverberation in your answer.

A tree is standing in the middle of a meadow. As you watch, the wind begins to blow and the tree bends. Which statement best explains how you could tell that a net force was acting on the tree? OA) The tree had momentum.

Consider two cars, a 700kg Porsche and a 600kg Honda Civic. The Porsche is speeding along at 40 m/s (mph) and the Civic is going half the speed at 20 m/s.

Which statement about an electron in the 4d state is correct? A. The magnitude of its orbital angular momentum is 6√ℏ. B. The largest orbital angular momentum it could have in any given direction is 4ℏ. C.

A D note has a frequency of 587.33 Hz. Calculate its wavelength in meters. The speed of sound is 343 m/s

A cyclist allows his bike to roll down a hill without pedaling. Towards the bottom of the hill he applies his brakes. The bike comes to a stop. Applying the brakes causes the brakes to warm up. Describe the energy transfers that have occurred.