Final answer:
To calculate the time it takes for a projectile to reach its highest point, use the kinematic equation for vertical motion. With an initial vertical velocity of 40 m/s, and using the acceleration due to gravity, the projectile reaches its highest point in approximately 4.08 seconds.
Step-by-step explanation:
The question pertains to calculating the time it takes for a projectile to reach its highest point in its trajectory, known as the time of ascent. The initial vertical velocity of the projectile is given as 40 m/s. To find the time of ascent, we use the kinematic equation for vertical motion with constant acceleration due to gravity (g = 9.81 m/s2), which is v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Since the velocity at the highest point is 0 m/s (the projectile is momentarily stationary at the highest point), we set v = 0 m/s and solve for t:
0 m/s = 40 m/s + (-9.81 m/s2 × t)
t = 40 m/s / 9.81 m/s2
t ≈ 4.08 seconds
Therefore, it takes approximately 4.08 seconds for the projectile to reach the highest point in its trajectory.