When I accelerate the car shakes above 50 MPH when I stop accel. shake stops. Any ideas Thanks

This is normal in a lot of cars when the hit high speeds around eighty. If it's happening to you at fifty miles per hour, then you may need to take it to the shop. There are a lot of factory into the cars shaking. Aerodynamics being the main problem. Your car isn't going to blow up or cut off, but you will be paing more in gas with all the resistance.

I would balance the tires first, and if that's not the problem, I would check the alignment. Good luck!

its probably the alignment.

Jack each tire up off the ground. Grab it and see if there is any "play" both side to side, then top to bottom. Play can be defined as...say....loose wiggle. It would be as little as a millimetre, and this would indicate a bearing on it's way out. At the fronts, however, be aware of worn tie-rod-ends. If you stick your head in the wheel well and look at the steering rack, move the tire and view where the "slop" is coming from. If the tire jiggles see if the arm of the rack moves and trace it to the tie rod end. Take a look.

If all is "firm", not refering to my "goat-ness" ROFL !!! ....then I concur with my friends' posts above.....likely it tire(s) out-of-balance.