An engineering student is gathering data on the motion of a model car traveling down a ramp. If energy is conserved, the potential energy of the car at the top of the ramp should equal the kinetic energy at the bottom of the ramp. After the first trail, the student calculates that the kinetic energy at the bottom of the ramp is less than the potential energy at the top of the ramp. Which of the following best explains the difference?​ A. the student did not include the effect of friction in his calculation
B. the student accidentally accelerated the car at the top of the ramp
C. the measure height of the ramp was less than the actual height
D. The car gained a small amount of mass as it moved down the ramp

What is the order of the moon, earth, and sun in a lunar eclipse and a solar eclipse?

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)