Answer:
The person with locked legs will experience greater impact force.
Explanation:
Let the two persons be of nearly equal mass (say m)
The final velocity of an object (person) dropped from a height H (here 2 meters) is given by,
(
= acceleration due to gravity)
which can be derived from Newton's equation of motion,
Now, the time taken (say 
) for the momentum ( 
) to change to zero will be more in the case of the person who bends his legs on impact than who keeps his legs locked.
We know that,
Naturally, the person who bends his legs will experience lesser force since is larger.
Answer:
Some examples of the uses of a screw are in a jar lid, a drill, a bolt, a light bulb, faucets, bottle caps and ball point pens.
Explanation:
Guessing you want the average speed. We can multiple each speed by the time we spent going that speed, and them all together and then divide by the total time we spent in traffic to get the average speed. We spent a total of 7.5 minutes in traffic, so average speed = (12*1.5+0*3.5+15*2.5)/7.5 = 7.4 m/s
Answer:
a. 
b. 
must be the minimum magnitude of deceleration to avoid hitting the leading car before stopping
c. 
is the time taken to stop after braking
Explanation:
Given:
- speed of leading car,
- speed of lagging car,
- distance between the cars,
- deceleration of the leading car after braking,
a.
Time taken by the car to stop:
where:
, final velocity after braking
time taken
b.
using the eq. of motion for the given condition:
where:
final velocity of the chasing car after braking = 0
acceleration of the chasing car after braking
must be the minimum magnitude of deceleration to avoid hitting the leading car before stopping
c.
time taken by the chasing car to stop:
is the time taken to stop after braking
