A person on top of a wall of height 3.4 m stands near the edge, leans over and tosses a putty wad of mass 1.3 kg vertically into the air as shown in the figure below. The wad reaches a maximum of 4 m above the top of the wall. The wad then comes down and hits the ground near the bottom of the wall.

Calculate the kinetic energy of the putty wad when 1) it reaches its highest point, 2) the instant when passes the top of the wall, and 3) instant just before it hits the ground?

1) At the highest point, V = 0

What does that tell you about the kinetic energy then?

2) When it passes the top of the wall (going dwn), it has K.E. = M g H, where H = 4 m is the maximum height thrown.

3) K.E. = M g (H + h)
where h is the height of the wall.

To calculate the kinetic energy of the putty wad at different points, we can use the formula for kinetic energy:

Kinetic Energy (KE) = (1/2) * mass * velocity^2.

To find the velocity at each point, we can use the principles of conservation of energy. At any point in the motion, the total mechanical energy (sum of potential energy and kinetic energy) remains constant.

1) When the putty wad reaches its highest point:
At the highest point, the kinetic energy is zero as the velocity is zero. The entire mechanical energy of the putty wad is in the form of potential energy.
Potential Energy (PE) = mass * gravity * height,
where the height is 4 m + 3.4 m (height of the wall).

2) When the putty wad passes the top of the wall:
At the top of the wall, the putty wad has reached its maximum height and starts coming down. At this point, the potential energy is zero, and all the mechanical energy is in the form of kinetic energy.
Potential Energy (PE) = 0,
Kinetic Energy (KE) = Total Mechanical Energy = mass * gravity * height,
where the height is 4 m + 3.4 m (height of the wall).

3) Just before the putty wad hits the ground:
Just before the putty wad hits the ground, its potential energy is zero again, and all the mechanical energy is in the form of kinetic energy.
Potential Energy (PE) = 0,
Kinetic Energy (KE) = Total Mechanical Energy = mass * gravity * height,
where the height is 3.4 m (height of the wall).

Remember to convert the mass and height to SI units (kilograms and meters) before plugging them into the equations. Also, you need to know the value of gravitational acceleration (g) which is approximately 9.8 m/s^2 on Earth to perform the calculations.