Assuming it is on a horizontal surface:
friction = μR
R = 20g (g is gravity 9.81)
so Friction = 0.085 x 20g
Work done is force x distance
so Work done = 0.085 x 20g x 28
= 466.956 J
The answer is 1. 4 is incorrect because you can't really decrease the mass of the driver. 3 is incorrect because accelerating the driver would cause more damage than not. 2 is incorrect because decreasing the distance would only cause more damage. 1 is correct because by increasing the length of time the force acts on the driver helps reduce the speed of the driver and cause the drive to sustain less injuries. Hope that helps.
Answer:
Explanation:
Since the door that leads to the room is opened, this gives room for particles to move into the next identical room and divided into octants. Now the amount of space that can be occupied becomes double, the number of basic states has increased by 404916
frequency=4Hz
wavelength=5m
amplitude=1/2×2=1m
period=1/frequency
1/4=0.25seconds.
velocity=wavelength×frequency
=5×4
=20m/s
