I'll address the first part of your question regarding the average distance covered if the time taken is 10 seconds. To find the distance covered when the time is known, you need to know the speed or velocity of the object.
Without the speed or velocity given, we cannot determine the distance covered accurately. Therefore, based on the information provided in the question, it's not possible to calculate the average distance covered within 10 seconds.
Moving on to the next part of your question where you are asked to define certain terms:
(a) Speed: Speed is a measure of how quickly an object moves. It is calculated as the distance traveled per unit of time, such as meters per second (m/s) or miles per hour (mph).
(b) Velocity: Velocity is similar to speed but includes the direction of motion. It is a vector quantity that specifies both the speed and direction of an object's motion.
(c) Uniform acceleration: Uniform acceleration occurs when an object's velocity changes by the same amount in each equal time period. This means that the object's acceleration remains constant over time.
Regarding the acceleration of a body in horizontal motion being equal to zero, this happens when the object is moving at a constant speed without any change in velocity. In this case, the net force acting on the object is balanced, resulting in zero acceleration.
Lastly, for the scenario of a car traveling at 50 m/s from rest covering a distance of 10 km in 40 minutes, you can calculate the average speed by dividing the total distance by the total time taken. This will give you the average speed of the car over the entire journey.
