In first gear, or low gear, an automobile's engine runs about three times as fast as the drive shaft. In second gear, the
engine does not have to run as fast; usually it runs about 1.6 times faster than the drive shaft. Finally, in third, or high
gear, the engine runs at the same speed as the drive shaft.
Engine speed = 2,100 r.p.m.
Transmission in first gear
Drive-shaft speed:


Answer :

Engine is currently in first gear as mentioned in question

  • Speed=2100rpm

Drive shaft speed be x

  • 3x=2100
  • x=700rpm

Answer:

700 rpm

Step-by-step explanation:

A driveshaft is a shaft that transmits mechanical power.

Its speed is measured in rpm (revolutions per minute).

Engine speed

  • First gear: 3 × drive-shaft speed
  • Second gear: 1.6 × drive-shaft speed
  • Third gear:  equal to drive-shaft speed

Given engine speed:

  • 2,100 rpm

Therefore, the drive-shaft speeds in the different gears are:

First gear

Drive-shaft speed = 2100 ÷ 3 = 700 rpm

Second gear

Drive-shaft speed = 2100 ÷ 1.6 = 1312.5 rpm

Third gear

Drive-shaft speed = 2100 rpm