A ball is thrown vertically upward. If upward is taken as positive, which statement is correct for its motion under gravity?
AIts acceleration is $+g$ throughout the motion
BIts acceleration is $-g$ throughout the motion
CIts acceleration is zero at the highest point only
DIts acceleration changes from $-g$ to $+g$ during descent
Answer & Solution
Correct answer: B. Its acceleration is $-g$ throughout the motion
Gravity acts downward at all times. If upward is positive, the acceleration due to gravity is negative, so the ball has acceleration $-g$ throughout ascent, at the top, and during descent.
Related questions
A ball is projected upwards from a height $h$ above the surface of the earth with velocityA ball is thrown vertically upwards. Which of the following graph/graphs represent velocitA stone projected with a velocity $u$ at an angle $\theta$ with the horizontal reaches maxA block $P$ of mass $m$ is placed on a frictionless horizontal surface. Another block $Q$ The potential energy between two atoms in a molecule is given by $U(x) = \frac{a}{x^{1/2}}A particle which is constrained to move along the $x$-axis, is subjected to a force in theTwo particles of masses $m_1$ and $m_2$ in projectile motion have velocities $\vec{u}_1$ aA thin uniform circular disc of mass $M$ and radius $R$ is rotating in a horizontal plane