# Science: Physics

 .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } What is speed? And what is it measured in? Speed is the distance an object travels in a certain time. It is measured in meters per second (m/s) or kilometers per hour (km/h). It is how fast an object travels. What is distance and what is it measured in? Distance is how far an object travels. It is measured in millimeters (mm), centimeters (cm), meters (m) or kilometers (km). What is time and what is it measured in? Time is how long it takes for an object to travel. It is measured in seconds (s), minutes (m) or hours (h). What to you use to find speed, time or distance of an object? You use an STD triangle. Set out like S and T, bottom layer. And D top layer. So, to find speed you divide the distance (D) by the time (T), and to find distance you multiply speed (S) by the time (T) etc. What is a distance-time graph? A distance time graph shows the time that is taken to travel a certain distance. The slope of the graph represents the speed of the object. What does a straight line on a DT graph mean? A straight line means that the object is traveling at a constant speed. What does a horizontal line represent on a DT graph? A horizontal line represents the object being still or stationary. If slope A is more steep than slop B, what does it mean about the speeds of the objects? It means that object A is moving at a faster speed, as it is covering more distance in a shorter time-frame. What does it mean when an object is not a straight line? And give visual examples of accelerating objects and decelerating objects. If the line is not straight it means that the object is changing speed. If it is an upward curve, similar to half a U, the object is accelerating as it is covering more distance in less time. If the line is an downward curve like a lower-case R, the object is accelerating, as it is covering less distance in more time. How much is earths gravity? And how do you find a person who is 40kg weight. Earths gravity is 10, and to find that persons weight you multiply the gravity by their mass. So, 40 x 10 = 400, meaning that their weight on earth is 400N (Newtons). What prevents a car from sliding out when it turns a corner? Friction. Why is it easier for a car to slide out around a corner on a gravel road? Because the gravel is loose off the ground, there is less friction keeping the car on the road. .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } Authornzsurfer ID46419 Card SetScience: Physics DescriptionSTD - What you need to know? Updated2010-11-01T06:28:03Z Show Answers