Physics L4 www.slideshare.net/DMS_physics

Key Terms acceleration average speed elapsed time free fall instantaneous speed rate relative scalar speed vector velocity

acceleration

average speed

elapsed time

free fall

instantaneous speed

rate

relative

scalar

speed

vector

velocity

Class Review Problems P.25 / 12 P.26 / 18, 21, 28, 30 P.27 / 52 P.26 / 32

P.25 / 12

P.26 / 18, 21, 28, 30

P.27 / 52

P.26 / 32

p.25 / 12 What is the acceleration of a car that travels in a straight line that increases its speed from zero to 100 km/h in 10s ?

What is the acceleration of a car that travels in a straight line that increases its speed from zero to 100 km/h in 10s ?

p.26 / 18 Toss a ball upwards. What is the change in speed each second on the way up ? on the way down ?

Toss a ball upwards. What is the change in speed each second

on the way up ?

on the way down ?

p. 26 / 21 How far will a freely falling object have fallen from a position of rest when its instantaneous speed is 10 m/s ?

How far will a freely falling object have fallen from a position of rest when its instantaneous speed is 10 m/s ?

p.26 / 26 Calculate the average speed of a cheetah that runs 140 m in 5 s.

Calculate the average speed of a cheetah that runs 140 m in 5 s.

p.26 / 28 Calculate the acceleration of a car that can go from rest to 100km/h in 10s.

Calculate the acceleration of a car that can go from rest to 100km/h in 10s.

p.26 / 30 Calculate the speed of a skateboarder who accelerates from rest for 3s down a ramp at an acceleration of 5m/s 2 .

Calculate the speed of a skateboarder who accelerates from rest for 3s down a ramp at an acceleration of 5m/s 2 .

Reaction Time (p.27/52) Calculate the reaction time of a person by dropping a ruler and letting the other person catch it. Measure the distance dropped in this time What is the reaction time?

Calculate the reaction time of a person by dropping a ruler and letting the other person catch it.

Measure the distance dropped in this time

What is the reaction time?

p.26 / 32 An object is dropped from rest and falls freely. After 6s, calculate its: instantaneous speed average speed distance fallen

An object is dropped from rest and falls freely. After 6s, calculate its:

instantaneous speed

average speed

distance fallen

Homework Assignment P.26 / 27, 29, 33, 53

P.26 / 27, 29, 33, 53

Homework Assignment P.26 / 27 A) calculate the average speed of Charlie, who runs to the store 4km away in 30 min. B) calculate the distance that Charlie runs if he maintains this average speed for 1h.

P.26 / 27

A) calculate the average speed of Charlie, who runs to the store 4km away in 30 min.

B) calculate the distance that Charlie runs if he maintains this average speed for 1h.

Homework Assignment P.26 / 29 Calculate the instantaneous speed at the 10s mark for a car that accelerates at 2m/s 2 from a position of rest.

P.26 / 29

Calculate the instantaneous speed at the 10s mark for a car that accelerates at 2m/s 2 from a position of rest.

Homework Assignment P.26 / 33 Calculate the instantaneous speed and distance for an object that that falls freely from rest for 8 seconds.

P.26 / 33

Calculate the instantaneous speed and distance for an object that that falls freely from rest for 8 seconds.

Homework Assignment P.26 / 53 Calculate your personal “hang time”, the time your feet are off the ground during a vertical jump.

P.26 / 53

Calculate your personal “hang time”, the time your feet are off the ground during a vertical jump.

Homework Assignment P.26 / 27, 29, 33, 53 (for problem texts see previous slides)

P.26 / 27, 29, 33, 53

(for problem texts see previous slides)

End L4 www.slideshare.net/DMS_physics