Would humans be able to cope? What would the effects of the gravity have on our infrastructure, and would animal life be able cope with the increase of gravity?
I would expect an increase in gravity by 50% to herald in a round of seismic activity like the world has never seen. Expect basically every coastal city to be wiped out by tsunamis in the first week.
Also, expanding on JDlugosz's comment about infrastructure and Matt's counter, while infrastructure typically has a safety factor, its typically evaluated in a steady state situation. You have the most dynamic environment possible: an instantanious increase in forces. More buildings would collapse than one might expect.
Infrastructure would not cope. Structures are engineered to be as strong as needed, so would not in general handle it long term.
Plants are only strong enough, so trees would fall, stems would bend over, etc.
Animals likewise: elephants would be crippled; ants would not carry the loads they need to, bugs could not fly, etc.
The atmosphere would be compressed down. Now the air sliding down the mountains can give Los Angeles summer-like weather at Christmas. So compressing all air on Earth by such an amount would turn the surface into an oven, rendering the other points moot.