The escape velocity for a projectile on the Earth's surface is 11.2 km/s. If a body is projected at twice this velocity, what happens? MCQ with Answer and Explanation

Question

The escape velocity for a projectile on the Earth's surface is 11.2 km/s. If a body is projected at twice this velocity, what happens?

A. It escapes Earth's gravity and retains a finite positive velocity in interstellar space.

B. It orbits the Earth indefinitely.

C. It returns to Earth after a long time.

D. It escapes Earth's gravity but eventually comes to rest in deep space.

Answer: Option A

Solution (By JKSSB Mock Tests)

Escape velocity (Ve) is the minimum velocity needed to overcome Earth's gravitational pull so that final velocity at infinity is zero. If launched with velocity v > Ve, the body will escape and, due to conservation of energy, retain a residual speed (v_infinity) at an infinite distance, calculated by v_infinity = √(v² - Ve²). Here, v = 2Ve, so it retains speed.

This question belongs to: Science Physics

Request complete Subject PDF

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1

Share Report

If the length of a wire is stretched to double its original length while keeping its volume constant, its new resistance will be:

A. Twice the original

B. Half the original

C. Four times the original

D. Unchanged

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Resistance R = rhoL/A. If the wire is stretched so length becomes L' = 2L, the volume (V = AL) must remain constant. Therefore, the new area A' must be A/2 to maintain V. The new resistance R' = rho(2L)/(A/2) = 4 * (rhoL/A) = 4R. Stretching a wire to double its length increases its resistance strictly by a factor of 4. This is a classic trap question compared to merely 'changing the wire'.

This question belongs to: Science Physics

Question #2

Share Report

In which of the following scenarios is the work done physically zero?

A. A person pushing a heavy wall that does not move.

B. All of the above.

C. A satellite moving in a circular orbit around the Earth.

D. A person carrying a heavy load on his head and walking on a horizontal road.

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
Work (W) = F × d × cos(θ). In scenario A, displacement (d) is zero. In scenario B, the applied force (upward) is perpendicular to the displacement (horizontal), so cos(90°) = 0. In scenario C, the centripetal force (gravity) is perpendicular to the satellite's instantaneous direction of motion, so work done is zero. All cases yield zero work.

This question belongs to: Science Physics