Physicshard · Past Paper
A body is moved from rest along a straight line by a machine delivering constant power. The velocity at time t is proportional to:
At^(1/2)
Bt
Ct^2
D1/t
✓ Correct Answer: A — t^(1/2)
P = Fv = (ma)v = m(dv/dt)v. v dv = (P/m) dt. Integrating both sides, v^2 ~ t, so v ~ sqrt(t).
Share this question
More from Physics
- What is the SI unit of electric charge?
- The weight of an object is measured by which instrument?
- The value of Universal Gravitational Constant (G) is:
- A body is projected vertically upwards with a velocity u. It passes a point at height h at times t1 and t2. The sum t1+t2 is:
- The work done by a person in lifting a load of 20 kg to a height of 2 m is: (g=10)