00:01
Hello students, in the first question it is asked which force component is responsible for supplying centripetal force enabling the car to go around a horizontal banked surface and it is a frictionless surface.
00:15
So if the car is going in a horizontal banked curved surface, so let it be the car, in this case two forces will be acting that is one is the normal force and the weight due to gravity.
00:31
In this case the normal force has two components, one is vertical component and another one is horizontal component.
00:40
So here the vertical component counteracts the force due to gravity that is mg which is acting downwards and the only force that is responsible for enabling the car to continue around a horizontal curve is the normal component of horizontal component of normal force.
01:02
So the right option here is option c, the horizontal component of the normal force.
01:19
So for the first question option c is the right answer.
01:26
Now let's move to the option second question that is a baseball which is hit forward at an angle of 45 degree.
01:39
So let it be the axis x and y.
01:45
So the baseball is hit at an angle 45 degree upwards and this baseball takes a projectile motion and if it is taking projectile motion means after reaching the highest point it starts accelerating downwards and for takes a parabolic path.
02:04
So in this case let's see the options.
02:10
The acceleration of the baseball is zero when the ball is at its highest point in the arc.
02:17
So at this point the acceleration will be momentarily zero because during this the acceleration will be decreasing and at highest point it is zero and as it descends downwards the acceleration increases due to the acceleration due to gravity.
02:38
So the first option will be the right answer and the second option acceleration of the ball points downwards as the ball moves upwards.
02:54
So this is a free fall condition.
02:58
So in this case the acceleration always point downward regardless of the ball is moving upward or downward.
03:07
So the option b is also correct and the speed of ball is negative as it rises.
03:13
So we cannot see say the speed of ball is negative since speed is a scalar quantity.
03:20
So we cannot determine direction for this.
03:26
So this is a wrong statement and the fourth one the velocity and acceleration of the rock always points in the same direction...