Question

Please answer all questions thanks. (1) A ball is thrown vertically up into the air. You...

(1) A ball is thrown vertically up into the air. You know that the ball rises while slowing down, then it is for a moment at rest, then it speeds back up while it heads down toward the ground. At the moment in time when the ball is at its very highest point in the trajectory, the net force on the ball is ...

a. zero because the ball is at rest.

b. the weight force on the ball.

c. the inertia of the ball down.

d. the mass of the ball down.

(2) A ball is thrown vertically up into the air. You know that the ball rises while slowing down, then it is for a moment at rest, then it speeds back up while it heads down toward the ground. At the moment in time when the ball is at its very highest point in the trajectory, the acceleration of the ball ...

a. is zero because the ball is at rest at that moment.

b. is 9.8 m/s/s.

c. depends on how heavy is the ball.

d. is 9.8 m/s/s down.

(3) The total thrust of the engines on a jet airplane is 8.8 * 105 N. If the acceleration of this plane is 2.9 m/s/s, what is the mass of the plane?

a. 3.0 * 105 kg

b. 4.4 * 105 kg

c. 4.7 * 105 kg

d. 2.7 * 105 kg

(4)A 1200 kg car has become stalled on an icy patch of flat horizontal road. Two ropes are attached to it and they exert forces of F1=800 N at 35o North of East, and F2=600 N at 25o South of East. What is the acceleration of the car if there is no friction?

Take East to be represented by  and North to be represented by .

m/s/s

m/s/s

m/s/s

m/s/s

Earn Coins

Coins can be redeemed for fabulous gifts.