Choice-C is a correct statement.
His speed is exactly (350/27) miles per second ... about 46,667 mph. Wotta guy !
××

×
50N is your force and the acceleration is -9.8m/s^2 due to gravity.
So, you just plug that in.

BUT you know that mass cannot be negative, so you just disregard the negative sign and the mass of the rock is 5.102 grams.
Answer:
okay sooo the weight is: 294 n
the normal force is 286 n
the acceleration is: -0.38 m/s²