Question

Which kinematic equation would you use to find the velocity of a skydiver 2.0s after she jumps from a plane and before she opens her parachute? Assume the positive direction is downward.

a) ( v = u + at )

b) ( v = u - gt )

c) ( s = ut + frac{1}{2}at^2 )

d) ( v = u - 2gt )

Answer 1

The correct equation to find the velocity of a skydiver 2 seconds after a jump is 'v = u + at'. Using the values, the velocity after 2 seconds is 19.6 m/s downward, making option a) the correct choice.

Step-by-step explanation:

To find the velocity of a skydiver 2.0 seconds after she jumps from a plane before she opens her parachute, and assuming that the positive direction is downward, we need to use a kinematic equation that relates initial velocity, acceleration, and time to the final velocity. The correct kinematic equation to use in this scenario would be v = u + at, where:

• v is the final velocity,
• u is the initial velocity (which is 0 if she starts from rest),
• a is the acceleration due to gravity (9.8 m/s² downward), and
• t is the time elapsed since the start of the fall (2.0 seconds).

Using the given values, we can calculate the skydiver's velocity after 2 seconds as:

v

= 0 + (9.8 m/s²) × (2.0 s) = 19.6 m/s downward. Therefore, the correct option to mention in the final part of the answer is option a.