from kinematics equation if we know that final speed is ZERO and initial speed is given that due to constant deceleration the object will stop in some distance "d" and this distance can be calculated by kinematics
here acceleration due to friction will be same at all different speed
so for 45 km/h speed the distance of stop is 15 m
while at other speed 112.5 km/h the distance will be unknown
now we will have
now divide above two equations
So it will stop in distance 93.75 m
Answer:
We know ForceF=mass×acceleration----------(1)
And given ForceF=
r
mv
2
----------(2)
Equating 1 and 2 dimensionaly we get ,
ma=
r
mv
2
MLT
−2
=ML
2
T
−2
L
−1
MLT
−2
=MLT
−2
Answer:
C. Both a and b
Explanation:
Firstly, persons and objects in a moving plane as described in this question, are moving at the same speed as the plane even if there is no individual movement of these objects.
However, this question describes a person sitting still in a moving plane. This means that;
- The person is motionless in relation to everything in the plane i.e the person is not moving even if other things in the plane are.
- The person is in motion compared to everything on the ground i.e. the person is moving at the same speed as the plane, hence, in comparison with the ground, the person is moving.
Therefore, options A and B are correct
In physics<span>, a </span>force<span> is said to do </span>work if, when acting, there is a displacement of the point of application in the direction of the force. For example, when a ball is held above the ground and then dropped, the work done on the ball as it falls is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). so in the proble, <span>She does NO work since the force she applies to the case is vertical and the direction of motion is horizontal. Work is the force times the parallel distance</span>
-- below the horizon
-- clear sky
