Answer:
(a) -472.305 J
(b) 1 m
Explanation:
(a)
Change in mechanical energy equals change in kinetic energy
Kinetic energy is given by
Initial kinetic energy is 
Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero
Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence
0-472.305 J=-472.305 J
(b)
From fundamental kinematic equation
Where v and u are final and initial velocities respectively, a is acceleration, s is distance
Making s the subject we obtain
but a=\mu g hence
Answer is B.
Because velocity is vector quantity, so magnitud and direction are needed to define it.
Since velocity means the speed(magnitude) of some object in a given direction, so it’s units are usually measured by meters/ seconds
Answer:
72000 miles
Explanation:
If the distance between the students is 600 miles, and this implies in a 3 degree difference in the sun position, that means this 600 miles is related to 3 degrees of the circunference of the planet.
So, to find the whole circunference of the planet, that is, 360 degrees, we just need to use a rule of three:
3 degrees -> 600 miles
360 degrees -> x miles
3x = 600 * 360
x = 600 * 360 / 3 = 72000 miles
The force that the student exerts on the floor of the elevator must be "(1) less than the weight of the student when at <span>rest" since the elevator is "beating" him downward.</span>
