D(m)
t(s)
the opposite (displacement - time) graph describes
the motion of a body moving in a straight line. is
the velocity of the body positive, negative or zero
at :
(a) t=1s
(b) t = 2 s
(c) t = 3 s

positive at (a) t = 1s

zero at (b) t = 2s

negative at (c) t = 3s

Explanation:

the motion of the object is positive at 1s because the line is being curves upwards. the motion of the object is zero at 2s because upwards motion has peaked, and downwards motion has not started yet. the motion of the object is negative at 3s because the line is curving downwards.

asthenosphere and convection

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.