A1200-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 9,000-kg truck moving in the same direction at 20.0 m/s. the velocity of the car right after the collision is 18.0 m/s to the east. a. what is the velocity of the truck right after the collision? b. how much mechanical energy is lost in the collision? account for this loss in energy.

May someone explain how to do this question?

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.