Speed is the distance traveled per unit of time. Velocity is an object's speed and direction of motion. Acceleration is a change in velocity over a certain period of time. Gravity tends to pull all objects toward the center of the earth. Gravitational Acceleration is the constant describing the acceleration of any object falling toward the earth. -9.8 m/sec2 -32 ft/sec2

Does a car’s speedometer measure speed, velocity or both? Only measures speed. It does not have a compass or GPS so it does not know if it got from point A to point B

No. Only measures speed. You need the direction. If an accurate speedometer registers a constant value for a period of time, can you determine the average velocity over that time period of time using only the speedometer? Explain. No. Only measures speed. You need the direction. It does not have a compass or GPS so it does not know if it got from point A to point B

Can the average velocity of a particle be zero over a given time interval if it is not zero over a shorter period of time interval? Explain? Example you go from 0-60 seconds and the average velocity is 0. But between 10 and 20 seconds the average velocity is 5. Is that possible? Yes if your direction changes from positive to negative. Forward +5 to backward -5 now average velocity 0 Or run on a track speed greater than zero but you end up at same point.

Can an object have varying velocity if its speed is constant Can an object have varying velocity if its speed is constant? It yes, give an example. Yes all about direction as example

Can an object have varying speed if its velocity is constant Can an object have varying speed if its velocity is constant? If yes, give an example No if the velocity is constant then the speed is constant and the direction

6)When an object moves with constant velocity, does its average velocity during any time interval differ from its instantaneous velocity at any instant? No because constant velocity means constant speed and constant direction

7) Can the velocity of an object be zero at the same instant its acceleration is not zero? Give an example Yes, shoot a cannon ball shot straight up in air and when it reaches maximum height the velocity is zero but its acceleration is -9.8 m/ss due the gravity.

8) If a car has greater maximum speed than another, does it mean that it has a greater acceleration? Explain using an example. No not. Maximum speed could be greater but the car may take longer to get up to speed.

9) Compare the acceleration of a motorcycle the accelerates from 80 km/h to 90 km/h with the acceleration of a bicycle that accelerates from rest to 10km/h in the same time. They would be the same

10) Can you conclude that a car is not accelerating if the speed indicates a steady 60km/h? No, same reason the direction matters

11) Can an object have a northward velocity and a southward acceleration? Yes if you are just slowing down.

12) Can the velocity of an object be negative when the acceleration is positive? Yes if you are just slowing down. What about vice versa? Yes if directions are opposite you are just slowing down.

Give an example where both the velocity and acceleration are negative. You are going to the left and speeding up. Or south and speeding up.

Same speed even though the first one will land first. 14) A rock is thrown vertically with a speed of v from the edge of a cliff. A second rock is thrown vertically downward at the same time with the same initial speed. Which rock has the greater speed when it reaches the bottom of the cliff? Assume no air resistance. Same speed even though the first one will land first.

A car is moving on a level road increases its speed from 16 m/s to 32 m/s in 10 seconds. What is the car’s acceleration? What is the car’s average speed?

A car is moving on a level road increases its speed from 16 m/s to 32 m/s in 10 seconds. What is average speed?

A ball at rest goes rolling down a hill at 3.3 m/s^2. If it accelerates for 7.5 seconds, how far will it travel? If it started at 4m/s, how far would it have traveled?

Given Vi=0, Vf=7m/s, a=1.4m/s (need time) Formula Vf^s = Vi^2 +2ad A sled going down a hill accelerates at 1.4 m/s. It started at rest, at what distance would it reach a speed of 7.00 m/s? Given Vi=0, Vf=7m/s, a=1.4m/s (need time) Formula Vf^s = Vi^2 +2ad 7^2 = 0^2 + 2*1.4m/s (d) 49=2.8*d 17.5 m = distance   Now you could solve for time as well

A jet goes from 0 to 1600m before take off A jet goes from 0 to 1600m before take off. It has a constant acceleration of 1.6 m/s What is the speed at take off What is the time required for takeoff?

A jet goes from 0 to 1600m before take off A jet goes from 0 to 1600m before take off. It has a constant acceleration of 1.6 m/s What is the time required to take off?

https://www.youtube.com/watch?v=M8xCj2VPHas Canon on a cliff