If you set the sine behaviour Movement field to "value only", you can then return a value between 0 and 1 in an action using the expression:

(object.sine.value+1)/2

You can then apply that expression to whatever variable you want the sine to be working on.

You can extend that formula to return a value between 0 an N:

N((object.sine.value+1)/2)

Assuming that you are using a side-on perspective, calculate the x and y velocities for the grenade - you can use the trig functions to determine these values, based upon how you control the grenade:

1) If your grenade is being thrown at a speed of S pixels per tick at an angle of A degrees then the x velocity is S*cos(A) and the y velocity is S*sin(A).

2) Every tick move your grenade at velocity X in the X axis and -velocity Y in the Y axis (the Y value is negative because the Y axis starts at zero at the top of the screen). Also you may need to reverse the X velocity if you are throwing the grenade to the left instead of the right.

3) You now have to account for gravity, otherwise your grenade will keep moving in a straight line. Gravity affects your y velocity. Create a global variable "gravity" and give it a small value. Each tick add the gravity value to the y velocity; you can play around with the gravity value until you find something that feels good.

You should now have a nice arc to your grenade. If you want the grenade to bounce on hitting the ground, multiply the y velocity by -1 on collision with the ground.

If you want to bounce the grenade off of a vertical wall multiply the x velocity by -1.

You will also need to apply some damping to the x and y velocities to reduce the grenade's speed each time it bounces, so also multiply both velocities on collision with the ground by a number less than 1.

One more thing - don't forget to multiply through by dt if you want the movement to be framerate independent.

Hope that works for you.

Some advice from an industry veteran (designer, 20 years for my sins...) for your daughter:

Hello! From the samples of your work posted you obviously have some chops, always a good starting point for working as a game artist, but before you plunge into a full-time course you should spend some time making sure that it's definitely the career path for you. Many skills you can pick up without attending a study programme, and if you do decide to go down the academic route you'll find it a much smoother journey with some prior knowledge under your belt.

1) Learn the tools of the trade: check out job vacancies for artists on games industry recruitment sites and familiarise yourself with the packages that the industry is demanding. Learn how art assets are implemented from these packages into different game engines and what the restrictions are when working with these tools.

2) Expand your repertoire: game art is more than just character design. Learn the basics of anatomy, animation, scenery design, typography, graphic design, HUD design visual effects, textures etc. Try different styles of art: pixel, vector, 3D, isometric, and learn how to implement these for different platforms. You will stand a much better chance of landing your first job in the industry if you can show versatility. As others on this thread have pointed out, it is rare to find a position that fits perfectly with your preferred areas of interest.

3) Study games, don't just play them. Consider how different systems were implemented and how you would go about replicating them. Make notes on what works and what doesn't. Play old games as well as new ones - learn about the constraints on old platforms that dictated the look and feel of the games on them.

4) Make some games! There's an abundance of free tools available (C2 of course!) that are easy to learn and can produce professional results - there's nothing like actually creating a game and seeing it through from start to finish to work out whether this is a career you want to pursue. In addition, help out others on projects - there are always people on this forum looking for help with art - give them a hand and get your work into their games and gain experience of working in a team (to deadlines!) in the process.

The more you can do in your free time to improve your portfolio and master the craft the more compelling a candidate you will be.

Final warning: life in the games industry can be tough; it's highly competitive, companies go bust, projects get canned, hours can be long. Try and secure some work experience with a games company first to get a feel as to whether it's the sort of lifestyle you will be comfortable with. If you're absolutely certain that games are the right path for you then go for a specialised course, otherwise a more general graphic design qualification would give you the flexibility to work in a whole range of fields, many that you may not have even heard of, whilst still allowing you to transition into games if you later feel that's where your gut is leading you.

Hope that helps!