True: when there is an angle between force and displacement, 
Explanation:
The work done by a force when pushing/pulling an object is given by the equation

where
F is the magnitude of the force
d is the displacement of the object
is the angle between the direction of the force and of the displacement
We have two extreme cases:
- When the force is parallel to the displacement, then
and
, so the work done is maximum and simply becomes

- When the force is perpendicular to the displacement, then
and
, so the work done is zero.
Learn more about work:
brainly.com/question/6763771
brainly.com/question/6443626
#LearnwithBrainly
J.J. Thompson is the scientist who recieved credit for discovering them.
A roller coaster car starts from the rest from a first summit, descends a vertical distance of 45 meters and then climbs a second summit, reaching the top with a speed of 15m / s. How high is the second summit? Do not consider friction