Chapter 3Chapter 3Kinematics in Two

Dimensions

3.1 – d, v, & a3.1 – d, v, & a

A bullet is fired horizontally. A second bullet is dropped at the same time and

at from the same height as the first bullet. Ignoring air resistance, which

bullet will hit the ground first?

…DEMONSTRATION…

3.2 – Kinematics Equations 3.2 – Kinematics Equations in 2-Din 2-DSame equations as Chapter 2.

The x component does not affect the y component of the motion.

Break the problem down into x and y directions; solve equations separately.

3.3 – Projectile Motion3.3 – Projectile Motion

3.3 – Projectile Motion3.3 – Projectile Motion

3.3 – Projectile Motion3.3 – Projectile Motion

ASSIGN:

Ch. 3 #14-26 (evens)

Due Thursday

1. A bus moving at a speed of 20 m/s begins to slow at a rate of 3 m/s each second. Find how far it goes before stopping.

66.7 m

2. An object starts from rest with constant acceleration of 8 m/s2 along a straight line. Find

(a)the speed at the end of 5 seconds.

(b) the average speed for the 5 second interval, and

(c) the distance traveled in the 5 seconds.

(a) 40 m/s, (b) 20 m/s, (c) 100 m

3. A stone is thrown straight upward and it rises to a height of 20 m. With what speed was it thrown?

(a) -17.4 m/s, (b) 3.8 s

4. A projectile is fired horizontally with a velocity of 30 m/s from the top of a 80 m high cliff.

(a)How long will it take to strike the level ground at the base of the cliff?

(b)How far from the foot of the cliff will it strike?

(c)With what velocity (vector) will it strike?

(a) T = 4.04 s, (b) 121m, (c) 50.0 m/s @ 53° S of

5. A baseball is thrown with an initial velocity of 100 m/s at an angle of 30° above the horizontal. How far from the throwing point will the baseball attain its original level?

884 m