An object moves with non-uniform acceleration. Then it have
1. Variable velocity and constant speed
2.Constant speed and velocity
3.Variable speed and constant velocity
4.Zero instantaneous velocity and non-zero speed
An object moves with non-uniform acceleration. Then it have
1. Variable velocity and constant speed
2.Constant speed and velocity
3.Variable speed and constant velocity
4.Zero instantaneous velocity and non-zero speed
It mentions about non uniform acceleration hence speed is not same its changing.
Velocity is vector component having direction acting as well.
option 1 cancels out because speed is not constant
same is for option 2
Option 3 is not valid becasue if speed is not constant velocity cannot
Hence Zero instantaneous velocity and non zero speed
Example Suppose you throw a ball upwards at some velocity vv. When you catch it again it's traveling downwards at (ignoring air resistance) a velocity of −v−v. So somewhere in between throwing and catching the ball it must have been stationary for a moment i.e. it's instantaneous velocity was zero. Obviously this was at the top of its travel.
When you throw the ball it immediately starts being accelerated downwards by the Earth's gravity, so it has a constant acceleration downwards of −9.81ms−2−9.81ms−2 (the acceleration is negative because it's reducing the velocity of the ball).
So this is an example of how there can be a non-zero acceleration (of −9.81ms−2−9.81ms−2) but there can be a moment when the ball's instantaneous velocity is zero.
Velocity is vector component having direction acting as well.
option 1 cancels out because speed is not constant
same is for option 2
Option 3 is not valid becasue if speed is not constant velocity cannot
Hence Zero instantaneous velocity and non zero speed
Example
Suppose you throw a ball upwards at some velocity vv. When you catch it again it's traveling downwards at (ignoring air resistance) a velocity of −v−v. So somewhere in between throwing and catching the ball it must have been stationary for a moment i.e. it's instantaneous velocity was zero. Obviously this was at the top of its travel.
When you throw the ball it immediately starts being accelerated downwards by the Earth's gravity, so it has a constant acceleration downwards of −9.81ms−2−9.81ms−2 (the acceleration is negative because it's reducing the velocity of the ball).
So this is an example of how there can be a non-zero acceleration (of −9.81ms−2−9.81ms−2) but there can be a moment when the ball's instantaneous velocity is zero.
