At a definite point, the bridge would begin oscillating to the matching rhythm as that
of the marching footsteps.
This oscillation would touch a determined peak when the bridge can
no longer tolerate its own
power and later collapses. So, soldiers are
systematic to break their steps
while passing a bridge.
Answer:
The work done is
Explanation:
Work is defined as the product of force and distance moved in the direction of application of force.
Given Data
distance S= 230m
force F= 140 N
Mass of car m= 1140 kg
Applying the formula for work done we have
The work done by pushing the car for a distance of is
Answer:
E = 12.9 kJ
Explanation:
Given that,
Mass of John, m = 55 kg
It is standing on the edge of a diving board which is at a height of 24 m.
We need to find his mechanical energy. The mechanical energy of John is equal to its potential energy such that,
E = mgh
E = 55 kg × 9.8 m/s² × 24
E = 12936 J
or
E = 12.9 kJ
So, his mechanical energy is equal to 12.9 kJ.
Answer:
Explanation:
When a body moves on a circular path , it undergoes a centripetal acceleration which is directed towards the centre . Whether the body moves clockwise or anticlockwise , the direction of centripetal acceleration will always oriented towards the centre.
The variation in tangential velocity will only change the magnitude of the acceleration but the direction of the centripetal acceleration will always be directed towards the centre.
So in the given case , change in the direction of rotation will not change the direction of centripetal acceleration. It will remain unchanged towards the centre.
overall change in direction of centripetal acceleration is zero.
Explanation:
Given that,
Bill is riding his bicycle at 5 m/s eastward: and Carlos is driving his car at 15 m/s westward.
Taking eastward as positive direction, we have:
is the velocity of Bill with respect to Amy (which is stationary)
is the velocity of Carlos with respect to Amy.
Bill is moving 5 m/s eastward compared to Amy at rest, so the velocity of Bill's reference frame is
Therefore, Carlos velocity in Bill's reference frame will be
So, the magnitude is 20 m/s and the direction is westward (negative sign).