Answer:
b. Friction decreased when he went from pavement to ice and then increased two more times.
Explanation:
Frictional force depends on the normal force of the surface and a friction coefficient.
Since we're talking about the same car, the value of will remain constant whereas μ will represent the change in the frictional coefficient of the surface. Now we consider the different surfaces, cars will slide in an icy road which means that the frictional coefficient is smaller than the pavement.
After Joshua returns to the pavement road, the resulting frictional force increases and will do so one more time when he reaches the gravel road. Gravel roads have greater frictional coefficients than pavement roads which means the frictional force will increase a second time.
1.) The object's Velocity
Faster it goes, more kinetic energy it has
Answer:
5 m/s²
Explanation:
Acceleration = change in speed/time taken
20-5=15
15/3= 5 m/s²
Let us first concentrate and write down all the information's already given in the question. Based on the information's the answer to the question can be easily deduced.
Distance traveled by the train = 225 km
Time taken to travel the distance of 225 km = 2.5 hours
Then
Average speed = Distance traveled/Time taken
= 225/2.5 km/hour
= 90 km/hour
So the average speed of the train is 90 kilometers per hour. The procedure for doing this kind of problem is described and it is the simplest way of solving such problems. I hope you have understood the process and got the answer you were looking for.
Answer:
Sound is produced when an object vibrates, creating a pressure wave. This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. As the particles vibrate, they move nearby particles, transmitting the sound further through the medium.