Answer:
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
