Speed= distance/time
Speed= 150000m/7200s=20.83m/s(cor.to.2d.p.)
A. The English system uses one unit for each category of measurement.
At First, there is chemical Energy( in your muscels) which is Used to Push down the spring. This Energy becomes the Energy of the spring, which increases until you stop pushing. If you Put your hand away, the Energy of the spring will become kinetic energ. This Energy is at the highest Level the Moment the book ist Leaving the spring. Afterwards, the kinetic Energy decreases while the Gravitational Potential Energy increases.
Answer:
Answer (b)
Explanation:
Acceleration is the rate of change of velocity in time, therefore constant acceleration will be changing velocity in direct proportion to time and will have a linear plot on a velocity/time chart. This eliminates answer (d) which has an increasing acceleration in time
answer (a) has a negative slope so the acceleration would be considered negative
answer (c) has zero slope so acceleration is zero and velocity is constant.
answer (b) has the required positive slope and acceleration
Answer:
speed of white ball is 1.13 m/s and speed of black ball is 2.78 m/s
initial kinetic energy = final kinetic energy

Explanation:
Since there is no external force on the system of two balls so here total momentum of two balls initially must be equal to the total momentum of two balls after collision
So we will have
momentum conservation along x direction

now plug in all values in it

so we have

similarly in Y direction we have

now plug in all values in it

so we have


now from 1st equation we have



so speed of white ball is 1.13 m/s and speed of black ball is 2.78 m/s
Also we know that since this is an elastic collision so here kinetic energy is always conserved to
initial kinetic energy = final kinetic energy

