Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. in one test, this gun accelerates a 5.0-kg projectile from rest to a speed of 4.0 × 103 m/s. the net force accelerating the projectile is 4.9 × 105 n. how much time is required for the projectile to come up to speed?

The time taken by the projectile to reach the required speed is 41 ms.

Calculate the acceleration  a of the projectile of mass m, using Newton's second law.

Substitute 5 kg for m and 4.9×10⁵N for F, the force needed for acceleration.

Use the equation of motion to determine the time taken by the projectile to reach a speed v from rest under the acceleration calculated.

Substitute 4.0×10³m/s for v, 0 for u and 9.8×10⁴m/s² for a.

The time taken to reach the required speed is 41 ms.

battery with hi vtge high val resist in series

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.