Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8 
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0 
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2 
Answer:
Musculoskeletal disorders (MSD) are injuries or disorders of the muscles, nerves, tendons, joints, cartilage, and spinal discs.
Explanation:
Answer:
Explanation:
initial velocity = 24m/s
final velocity = 0 ( since she is coming to a rest )
time = 12 s
∴ acceleration = final velocity - initial velocity / time
= 0 -24 / 12
= -24/12
= -2 m/s
hope this helps
plz mark it as brainliest