Q 2 1 Find the kinetic energy of

Q 2: 1. Find the kinetic energy of the ball having mass 0. 5 kg and velocity 10 m/s. 2. Find the Kinetic Energy of the object at 14 m from the given graph on the right. 3. Look at the given picture below. If the final velocity of the box is 4 m/s find the work done by friction.

Q 2: 1. Find the kinetic energy of the ball having mass 0. 5 kg and velocity 10 m/s. M = 0. 05 kg V = 10 m/s KE = ? . 5 kg x (10 m/v)2 25 kg m 2 s 2 25 kg J

2. Find the Kinetic Energy of the object at 14 m from the given graph on the right. 5 N X 4 m = 20 JN*m 5 N X 12 m = 60 JN*m ½ 5 N X 4 m = 10 J N*m ½ 5 N X 2 m = 5 J N*m Total KE = 20 + 60 + 10 + 5 = 95 J

3. Look at the given picture below. If the final velocity of the box is 4 m/s find the work done by friction. Etotal = PE + KE Etotal = mgh PE + ½ KE mv 2 Etotal = 5 kg * 9. 8 m/s + ½ 5 Kg *(4 m/s)2

In this activity we will explore what happens when two spheres collide.

Did the term “momentum” come up in your discussions? Momentum can be defined as "mass in motion. " All objects have mass; so if an object is moving, then it has momentum - it has its mass in motion.

The amount of momentum that an object has is dependent upon two variables: 1. Mass 2. Velocity The units are usually a mass unit times a velocity unit…usually kg*m/s (but not always). Because it has direction, it is a vector.

Every baseball player dreams of hitting a home run. When a player hits the ball, at the moment of collision, the ball and the bat are deformed by the condition. The resulting change in momentum determines the batter’s success. Think about this: What is the force on a baseball bat when a home run is hit out of the park?

How are the velocities before and after the collision related to the force acting on it?

According to Newton’s 2 nd Law, when the ball collided with the force provided by the bat, its acceleration must have changed: f = ma. Notice how the force of on the ball changes. Just after contact, the ball is squeezed & force increases. The ball is deformed but returns to its shape and snaps away from the bat. The force rapidly returns to zero.

What is the maximum force applied on the baseball? 14, 700 N or 1. 47 X 10 4 N A baseball weighing 5. 25 ounces, is equivalent to 1. 95 N. The force of the bat is more than 10, 000 times the weight of the ball.

Is it possible to determine how long the collision lasted? The whole thing happened in about 3. 0 milliseconds. The area under the curve is called the impulse.

J

Momentum of an object is equal to the mass of the object times the object’s velocity.

A 2200 kg vehicle traveling at 94 km/h can be stopped in 21 s by gently applying the breaks. It can be stopped in 3. 8 s if the driver slams on the brakes, or in. 22 s if it hits a concrete wall. What is the average force exerted on the vehicle in each of these stops?

Assignment: Page 233 1 - 5 Due Friday