A train starts from its station and it velocity reaches 200m/s in 5
seconds. What is its acceleration?

a. 400m/s
b. 40m/s2
c. 4.5m/s2
d. Initial velocity is missing

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves

What kind of simple machine is a catapult?