Which of the following statements is correct for an object released from rest, freefalling in the Earth's gravity? (Neglect air resistance.) Circle all true statements. If the statement is incorrect rewrite the statement, in the space below the incorrect statement, to make it correct. a. during each second the object travels 4.9 m b. the average speed at time t = 4s is 39.2 m/s c. the instantaneous speed at time t = 3s is 29.4 m/s d. the average acceleration at time t = 1s is 9.8 m/s2 e. the average acceleration at time t = 3s is 29.4 m/s2

a. During each second the object travels 4.9 m

The distance, s, the object traveled each second is s = (u × 1 + 4.9) meters

b. The average speed at time t = 4s is 39.2 m/s

the average speed at t = 4 second  is 78.4 m/s

c. The instantaneous speed at time t = 3 s is 29.4 m/s

The instantaneous speed at time t = 3 s is 44.145 m/s

d. The average acceleration at time t = 1 s is 9.8 m/s² is correct

e. The average acceleration at time t = 3 s is 29.4 m/s²

The average acceleration at time t = 3 s is 9.81 m/s²

Explanation:

a. During each second the object travels 4.9 m

The distance, s, the object traveled each second is s = (u × 1 + 4.9) meters

b. The average speed at time t = 4 s is 39.2 m/s

The speed is given by the following equation;

v = u + g·t

Where;

u = The initial velocity =  m/s

g = The acceleration due to gravity

t = The time

At the third second, the speed is given as follows;

t = 3 s

v = 0 × 3 + 1/2×9.81×3² = 44.145 m/s

At the fourth second, the speed is given as follows;

t = 4 s

v = 0 × 4 + 1/2×9.8×4² = 78.4 m/s

Therefore, the average speed at t = 4 second  is 78.4 m/s

Similarly

The distance covered at t = 4 = 1/2×9.8×4² = 78.4

The time = 1 s

Average speed = Distance/Time = 78.4/1 = 78.4 m/s

c. The instantaneous speed at time t = 3 s is 29.4 m/s

The instantaneous speed is given by the following equation;

v = u + g·t

At the third second, the speed is given as follows;

t = 3 s

v = 0 × 3 + 1/2×9.81×3² = 44.145 m/s

The instantaneous speed at time t = 3 s is 44.145 m/s

d. The average acceleration at time t = 1 s is 9.8 m/s²

The acceleration of the object in free fall is constant and equal to 9.8 m/s²

e. The average acceleration at time t = 3 s is 29.4 m/s²

Neglecting air resistance, an object in free fall has a constant negative acceleration of 9.81 m/s²

Therefore, the average acceleration at time t = 3 s is 9.81 m/s²

an obstruction

a person with a mass of 106kg has a weight of 1060n